Shift Equivalency
Consider the set of B^N Ndigit numbers in base B, with lead zeros
being significant. Call two such numbers "shiftequivalent" if one can
be mapped to the other by a rotation or a reversal of a rotation.
This partitions the set into equivalence classes, each of which can
contain at most 2N elements.
For example, with B=10 and N=4, these are some equivalence classes:
{1357,3571,5713,7135,7531,5317,3175,1753},
{1111},
{1122,1221,2211,2112},
{1313,3131}
For B=N=10, two problems:
Compute the number of equivlence classes.
Exhibit an equivalence class with a maximal number of primes.
