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.

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

Table of n, a(n) for n=1..100.

N. J. A. Sloane and others, Sequences of RADD type, OEIS wiki.

Crossrefs

Cf. A117828, A117800, A118879.

Sequence in context: A156741 A138730 A159821 * A036208 A119903 A113796

Adjacent sequences: A118875 A118876 A118877 * A118879 A118880 A118881

Keyword

nonn,base

Author

N. J. A. Sloane, May 26 2006

Status

approved