This article explores the search for SP numbers, finding the few
that exist and the proof that there are no more.
This article discusses what happens, and why, if you generate
chains of sequences getting the next sequence from the differences
between the adjacent terms in the sequence before it, eg (7, 2, 8,
3). . . .
Investigate the sequences obtained by starting with any positive 2
digit number (10a+b) and repeatedly using the rule 10a+b maps to
10b-a to get the next number in the sequence.
Find all the periodic cycles and fixed points in this number
sequence using any whole number as a starting point.