[jpkwohxs] Arrangements data

Create a mapping of permutations of subsets of playing cards to data.  These are arrangements, unless we also take advantage of the additional flexibility that some cards (namely A 3 5 7 9 of spades, hearts, clubs, but not diamonds) are different when rotated 180 degrees.

Create an app with which one can take a picture of a set of playing cards and have it translated to a string of letters.  (Also instructions for going the other way.)  We might use a dense encoding of English.

At least 227 bits possible as an arrangement; don't know how to count the additional possibilities from card rotation.

If cards have backs which are not 180-degree rotation symmetric, then even more data can be encoded, though not decodable just from the faces.