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A118878
Let T(S,Q) be the sequence obtaining by starting with S and repeatedly reversing the digits and adding Q to get the next term. a(n) is the number of steps for T(n,5) to reach a cycle, or -1 if no cycle is ever reached.
5
1, 190, 1, 87, 1, 0, 189, 0, 86, 0, 0, 188, 0, 85, 191, 0, 0, 95, 0, 190, 1, 0, 184, 0, 3, 187, 0, 0, 91, 0, 96, 0, 0, 180, 88, 0, 183, 0, 0, 87, 1, 92, 0, 0, 3, 84, 0, 179, 0, 0, 191, 0, 88, 0, 2, 190, 2, 87, 2, 1, 2, 97, 2, 192, 3, 0, 186, 0, 83, 189, 0, 0, 93, 0, 98, 0, 0, 182, 0, 1, 185, 0, 0, 89, 3, 94, 0, 0, 178, 86, 0, 181, 0, 0, 193, 0, 90, 0, 0, 1
OFFSET
1,2
COMMENTS
Is a(n) ever -1? If so then n > 10000.
The cycle has length 207 for S <= 1015, but for S = 1016 it has length 36 (see A118879).
LINKS
N. J. A. Sloane and others, Sequences of RADD type, OEIS wiki.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, May 26 2006
STATUS
approved