Tuesday, November 14, 2023

[hsfjokff] least prime factor of primorial minus one

we crudely attempt to extend OEIS A057713, the smallest prime factor of P# - 1, where P# is the primorial function.  previously, primorial+1, which explains more details.

some factors were found with Pari/GP and GMP-ECM.  other factors were gathered from https://oeis.org/A057713/b057713.txt , https://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha103.htm , and http://factordb.com .  the factor for nthprime(217)#-1 = primorial(1327) - 1 was not previously known.

the next prime is a factor for indices 2, 4, and no known further indices.

the prime factors listed below are not guaranteed to be smallest factors, because both Pollard rho and the Elliptic Curve Method is probabilistic.  this is why above we described this calculation as "crudely attempt to extend".

we ran GMP-ECM with its autoincrement flag (-I), and for completely unfactored entries below, we report the last B1 we tried.

nthprime(2)# - 1 = 3# - 1 = 5 is prime

nthprime(3)# - 1 = 5# - 1 = 29 is prime

nthprime(4)# - 1 = 7# - 1 = 209 is divisible by 11

nthprime(5)# - 1 = 11# - 1 is prime

nthprime(6)# - 1 = 13# - 1 is prime

nthprime(7)# - 1 = 17# - 1 is divisible by 61

nthprime(8)# - 1 = 19# - 1 is divisible by 53

nthprime(9)# - 1 = 23# - 1 is divisible by 37

nthprime(10)# - 1 = 29# - 1 is divisible by 79

nthprime(11)# - 1 = 31# - 1 is divisible by 228737

nthprime(12)# - 1 = 37# - 1 is divisible by 229

nthprime(13)# - 1 = 41# - 1 is prime

nthprime(14)# - 1 = 43# - 1 is divisible by 141269

nthprime(15)# - 1 = 47# - 1 is divisible by 191

nthprime(16)# - 1 = 53# - 1 is divisible by 87337

nthprime(17)# - 1 = 59# - 1 is divisible by 27600124633

nthprime(18)# - 1 = 61# - 1 is divisible by 1193

nthprime(19)# - 1 = 67# - 1 is divisible by 163

nthprime(20)# - 1 = 71# - 1 is divisible by 260681003321

nthprime(21)# - 1 = 73# - 1 is divisible by 313

nthprime(22)# - 1 = 79# - 1 is divisible by 163

nthprime(23)# - 1 = 83# - 1 is divisible by 139

nthprime(24)# - 1 = 89# - 1 is prime

nthprime(25)# - 1 = 97# - 1 is divisible by 66683

nthprime(26)# - 1 = 101# - 1 is divisible by 2990092035859

nthprime(27)# - 1 = 103# - 1 is divisible by 15649

nthprime(28)# - 1 = 107# - 1 is divisible by 17515703

nthprime(29)# - 1 = 109# - 1 is divisible by 719

nthprime(30)# - 1 = 113# - 1 is divisible by 295201

nthprime(31)# - 1 = 127# - 1 is divisible by 15098753

nthprime(32)# - 1 = 131# - 1 is divisible by 10172884549

nthprime(33)# - 1 = 137# - 1 is divisible by 20962699238647

nthprime(34)# - 1 = 139# - 1 is divisible by 4871

nthprime(35)# - 1 = 149# - 1 is divisible by 673

nthprime(36)# - 1 = 151# - 1 is divisible by 311

nthprime(37)# - 1 = 157# - 1 is divisible by 1409

nthprime(38)# - 1 = 163# - 1 is divisible by 1291

nthprime(39)# - 1 = 167# - 1 is divisible by 331

nthprime(40)# - 1 = 173# - 1 is divisible by 1450184819

nthprime(41)# - 1 = 179# - 1 is divisible by 23497

nthprime(42)# - 1 = 181# - 1 is divisible by 711427

nthprime(43)# - 1 = 191# - 1 is divisible by 521

nthprime(44)# - 1 = 193# - 1 is divisible by 673

nthprime(45)# - 1 = 197# - 1 is divisible by 519577

nthprime(46)# - 1 = 199# - 1 is divisible by 1372062943

nthprime(47)# - 1 = 211# - 1 is divisible by 56543

nthprime(48)# - 1 = 223# - 1 is divisible by 811

nthprime(49)# - 1 = 227# - 1 is divisible by 182309

nthprime(50)# - 1 = 229# - 1 is divisible by 53077

nthprime(51)# - 1 = 233# - 1 is divisible by 641

nthprime(52)# - 1 = 239# - 1 is divisible by 349

nthprime(53)# - 1 = 241# - 1 is divisible by 389

nthprime(54)# - 1 = 251# - 1 is divisible by 565921

nthprime(55)# - 1 = 257# - 1 is divisible by 777041

nthprime(56)# - 1 = 263# - 1 is divisible by 1176221

nthprime(57)# - 1 = 269# - 1 is divisible by 757

nthprime(58)# - 1 = 271# - 1 is divisible by 2341

nthprime(59)# - 1 = 277# - 1 is divisible by 44753

nthprime(60)# - 1 = 281# - 1 is divisible by 303665792864057405074693

nthprime(61)# - 1 = 283# - 1 is divisible by 7027

nthprime(62)# - 1 = 293# - 1 is divisible by 4111

nthprime(63)# - 1 = 307# - 1 is divisible by 1571

nthprime(64)# - 1 = 311# - 1 is divisible by 166661291

nthprime(65)# - 1 = 313# - 1 is divisible by 917337320621

nthprime(66)# - 1 = 317# - 1 is prime

nthprime(67)# - 1 = 331# - 1 is divisible by 7037216702504839

nthprime(68)# - 1 = 337# - 1 is prime

nthprime(69)# - 1 = 347# - 1 is divisible by 1609

nthprime(70)# - 1 = 349# - 1 is divisible by 33409

nthprime(71)# - 1 = 353# - 1 is divisible by 18422659

nthprime(72)# - 1 = 359# - 1 is divisible by 1069

nthprime(73)# - 1 = 367# - 1 is divisible by 1880785297

nthprime(74)# - 1 = 373# - 1 is divisible by 2705777831

nthprime(75)# - 1 = 379# - 1 is divisible by 6361

nthprime(76)# - 1 = 383# - 1 is divisible by 5407

nthprime(77)# - 1 = 389# - 1 is divisible by 104707

nthprime(78)# - 1 = 397# - 1 is divisible by 599

nthprime(79)# - 1 = 401# - 1 is divisible by 4139

nthprime(80)# - 1 = 409# - 1 is divisible by 35447

nthprime(81)# - 1 = 419# - 1 is divisible by 1986323

nthprime(82)# - 1 = 421# - 1 is divisible by 761

nthprime(83)# - 1 = 431# - 1 is divisible by 234277373353

nthprime(84)# - 1 = 433# - 1 is divisible by 1447641166619113176017

nthprime(85)# - 1 = 439# - 1 is divisible by 33073

nthprime(86)# - 1 = 443# - 1 is divisible by 16054891

nthprime(87)# - 1 = 449# - 1 is divisible by 1594387

nthprime(88)# - 1 = 457# - 1 is divisible by 4012079

nthprime(89)# - 1 = 461# - 1 is divisible by 23107891172756940484396791068944577893302431569651

nthprime(90)# - 1 = 463# - 1 is divisible by 631

nthprime(91)# - 1 = 467# - 1 is divisible by 11379319098532079

nthprime(92)# - 1 = 479# - 1 is divisible by 2609

nthprime(93)# - 1 = 487# - 1 is divisible by 494441

nthprime(94)# - 1 = 491# - 1 is divisible by 17929

nthprime(95)# - 1 = 499# - 1 is divisible by 569

nthprime(96)# - 1 = 503# - 1 is divisible by 3300480581931696902302732092200380863444990184404360359

nthprime(97)# - 1 = 509# - 1 is divisible by 593759939

nthprime(98)# - 1 = 521# - 1 is divisible by 3666321961

nthprime(99)# - 1 = 523# - 1 is divisible by 563

nthprime(100)# - 1 = 541# - 1 is divisible by 6014627

nthprime(101)# - 1 = 547# - 1 is divisible by 1777

nthprime(102)# - 1 = 557# - 1 is divisible by 53563779143263213754862638009468737

nthprime(103)# - 1 = 563# - 1 is divisible by 7867

nthprime(104)# - 1 = 569# - 1 is divisible by 12101

nthprime(105)# - 1 = 571# - 1 is divisible by 10753

nthprime(106)# - 1 = 577# - 1 is divisible by 1093

nthprime(107)# - 1 = 587# - 1 is divisible by 2113

nthprime(108)# - 1 = 593# - 1 is divisible by 10859

nthprime(109)# - 1 = 599# - 1 is divisible by 4003709

nthprime(110)# - 1 = 601# - 1 is divisible by 54273959359

nthprime(111)# - 1 = 607# - 1 is divisible by 69473

nthprime(112)# - 1 = 613# - 1 is divisible by 5659

nthprime(113)# - 1 = 617# - 1 is divisible by 5591

nthprime(114)# - 1 = 619# - 1 is divisible by 296071

nthprime(115)# - 1 = 631# - 1 is divisible by 7927

nthprime(116)# - 1 = 641# - 1 is divisible by 881

nthprime(117)# - 1 = 643# - 1 is divisible by 715927

nthprime(118)# - 1 = 647# - 1 is divisible by 109357

nthprime(119)# - 1 = 653# - 1 is divisible by 109673

nthprime(120)# - 1 = 659# - 1 is divisible by 76948279003051

nthprime(121)# - 1 = 661# - 1 is divisible by 224859040921421

nthprime(122)# - 1 = 673# - 1 is divisible by 38200012273

nthprime(123)# - 1 = 677# - 1 is divisible by 2803

nthprime(124)# - 1 = 683# - 1 is divisible by 8259773239673410178219

nthprime(125)# - 1 = 691# - 1 is divisible by 2063

nthprime(126)# - 1 = 701# - 1 is divisible by 2801

nthprime(127)# - 1 = 709# - 1 is divisible by 660924521623121209230107

nthprime(128)# - 1 = 719# - 1 is divisible by 315643

nthprime(129)# - 1 = 727# - 1 is divisible by 8101

nthprime(130)# - 1 = 733# - 1 is divisible by 5239123655163246348151

nthprime(131)# - 1 = 739# - 1 is divisible by 118387

nthprime(132)# - 1 = 743# - 1 is divisible by 57455597751970998877176249003156521

nthprime(133)# - 1 = 751# - 1 is divisible by 808823054396726705208944607100082721043

nthprime(134)# - 1 = 757# - 1 is divisible by 6637

nthprime(135)# - 1 = 761# - 1 is divisible by 7677996300827

nthprime(136)# - 1 = 769# - 1 is divisible by 1160227

nthprime(137)# - 1 = 773# - 1 is divisible by 638233

nthprime(138)# - 1 = 787# - 1 is divisible by 640227319

nthprime(139)# - 1 = 797# - 1 is divisible by 953

nthprime(140)# - 1 = 809# - 1 is divisible by 21991

nthprime(141)# - 1 = 811# - 1 is divisible by 3199720721

nthprime(142)# - 1 = 821# - 1 is divisible by 42844194023

nthprime(143)# - 1 = 823# - 1 is divisible by 1579031

nthprime(144)# - 1 = 827# - 1 is divisible by 14503

nthprime(145)# - 1 = 829# - 1 is divisible by 26987

nthprime(146)# - 1 = 839# - 1 is divisible by 1751693

nthprime(147)# - 1 = 853# - 1 is divisible by 20548103533

nthprime(148)# - 1 = 857# - 1 is divisible by 35573

nthprime(149)# - 1 = 859# - 1 is divisible by 246016739

nthprime(150)# - 1 = 863# - 1 is divisible by 746027341427

nthprime(151)# - 1 = 877# - 1 is divisible by 911

nthprime(152)# - 1 = 881# - 1 is divisible by 41134919254014829

nthprime(153)# - 1 = 883# - 1 is divisible by 1110311750119070976651453707

nthprime(154)# - 1 = 887# - 1 is divisible by 11257

nthprime(155)# - 1 = 907# - 1 is divisible by 983

nthprime(156)# - 1 = 911# - 1 is divisible by 109547

nthprime(157)# - 1 = 919# - 1 is divisible by 1181

nthprime(158)# - 1 = 929# - 1 is divisible by 30376905151

nthprime(159)# - 1 = 937# - 1 is divisible by 37811

nthprime(160)# - 1 = 941# - 1 is divisible by 1433

nthprime(161)# - 1 = 947# - 1 is divisible by 2153

nthprime(162)# - 1 = 953# - 1 is divisible by 38212861741

nthprime(163)# - 1 = 967# - 1 is divisible by 14771753

nthprime(164)# - 1 = 971# - 1 is divisible by 5737

nthprime(165)# - 1 = 977# - 1 is divisible by 14083

nthprime(166)# - 1 = 983# - 1 is divisible by 26633

nthprime(167)# - 1 = 991# - 1 is prime

nthprime(168)# - 1 = 997# - 1 is divisible by 106859

nthprime(169)# - 1 = 1009# - 1 is divisible by 521317

nthprime(170)# - 1 = 1013# - 1 is divisible by 112593828893724701195685754565695150560753586811

nthprime(171)# - 1 = 1019# - 1 is divisible by 41299

nthprime(172)# - 1 = 1021# - 1 is divisible by 389783

nthprime(173)# - 1 = 1031# - 1 is divisible by 28771

nthprime(174)# - 1 = 1033# - 1 is divisible by 11217725881

nthprime(175)# - 1 = 1039# - 1 is divisible by 1296546826589465489576348219482737598352223058436635171

nthprime(176)# - 1 = 1049# - 1 is divisible by 31127898314092269938684484007635727

nthprime(177)# - 1 = 1051# - 1 is divisible by 14969

nthprime(178)# - 1 = 1061# - 1 is divisible by 784423

nthprime(179)# - 1 = 1063# - 1 is divisible by 291503

nthprime(180)# - 1 = 1069# - 1 is divisible by 1327

nthprime(181)# - 1 = 1087# - 1 is divisible by 17299

nthprime(182)# - 1 = 1091# - 1 is unfactored, 458 digits, last B1=6448937

nthprime(183)# - 1 = 1093# - 1 is divisible by 330015654119

nthprime(184)# - 1 = 1097# - 1 is divisible by 256284923

nthprime(185)# - 1 = 1103# - 1 is divisible by 1283

nthprime(186)# - 1 = 1109# - 1 is divisible by 24407

nthprime(187)# - 1 = 1117# - 1 is divisible by 4157

nthprime(188)# - 1 = 1123# - 1 is divisible by 23469739

nthprime(189)# - 1 = 1129# - 1 is divisible by 4943

nthprime(190)# - 1 = 1151# - 1 is divisible by 1555074301957555828730151725339

nthprime(191)# - 1 = 1153# - 1 is divisible by 1424525332337

nthprime(192)# - 1 = 1163# - 1 is divisible by 1151633336245487868340531

nthprime(193)# - 1 = 1171# - 1 is divisible by 2437343

nthprime(194)# - 1 = 1181# - 1 is divisible by 227629

nthprime(195)# - 1 = 1187# - 1 is divisible by 102859

nthprime(196)# - 1 = 1193# - 1 is unfactored, 501 digits, last B1=5997526

nthprime(197)# - 1 = 1201# - 1 is divisible by 9234487357

nthprime(198)# - 1 = 1213# - 1 is divisible by 17347517031847

nthprime(199)# - 1 = 1217# - 1 is divisible by 27814739077

nthprime(200)# - 1 = 1223# - 1 is divisible by 3787687

nthprime(201)# - 1 = 1229# - 1 is unfactored, 516 digits, last B1=5788781

nthprime(202)# - 1 = 1231# - 1 is divisible by 167687809

nthprime(203)# - 1 = 1237# - 1 is divisible by 2311595977

nthprime(204)# - 1 = 1249# - 1 is divisible by 163236519283

nthprime(205)# - 1 = 1259# - 1 is divisible by 73979777

nthprime(206)# - 1 = 1277# - 1 is divisible by 1273457

nthprime(207)# - 1 = 1279# - 1 is divisible by 1383607

nthprime(208)# - 1 = 1283# - 1 is divisible by 19687

nthprime(209)# - 1 = 1289# - 1 is divisible by 1811

nthprime(210)# - 1 = 1291# - 1 is divisible by 4319941

nthprime(211)# - 1 = 1297# - 1 is divisible by 43913

nthprime(212)# - 1 = 1301# - 1 is divisible by 43329742931

nthprime(213)# - 1 = 1303# - 1 is divisible by 179866327

nthprime(214)# - 1 = 1307# - 1 is divisible by 440342341

nthprime(215)# - 1 = 1319# - 1 is divisible by 391579

nthprime(216)# - 1 = 1321# - 1 is divisible by 260189

nthprime(217)# - 1 = 1327# - 1 is divisible by 954765457247896375172877804352140973

nthprime(218)# - 1 = 1361# - 1 is divisible by 5320092072242699

nthprime(219)# - 1 = 1367# - 1 is divisible by 20681

nthprime(220)# - 1 = 1373# - 1 is divisible by 756923

nthprime(221)# - 1 = 1381# - 1 is divisible by 48299

nthprime(222)# - 1 = 1399# - 1 is divisible by 220307

nthprime(223)# - 1 = 1409# - 1 is divisible by 3911

nthprime(224)# - 1 = 1423# - 1 is divisible by 34217

nthprime(225)# - 1 = 1427# - 1 is divisible by 21637487

nthprime(226)# - 1 = 1429# - 1 is divisible by 6421

nthprime(227)# - 1 = 1433# - 1 is divisible by 86263

nthprime(228)# - 1 = 1439# - 1 is divisible by 3557

nthprime(229)# - 1 = 1447# - 1 is unfactored, 604 digits, last B1=11689233

nthprime(230)# - 1 = 1451# - 1 is divisible by 341816863

nthprime(231)# - 1 = 1453# - 1 is divisible by 8317

nthprime(232)# - 1 = 1459# - 1 is divisible by 7691

nthprime(233)# - 1 = 1471# - 1 is divisible by 1770787

nthprime(234)# - 1 = 1481# - 1 is divisible by 5331773

nthprime(235)# - 1 = 1483# - 1 is divisible by 1631647

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