A118510 Define sequence S_m by: initial term = m, reverse digits and add 1 to get next term. It is conjectured that S_m always reaches a cycle of length 9, as in A117230. Sequence gives records for number of steps to reach cycle.

1, 18, 19, 36, 37, 54, 55, 72, 73

Offset

1,2

Comments

The values of m which take this many steps are 1, 11, 101, 1001, 10001, 100001, 1000001, 10000001, 100000001, ...

Links

Table of n, a(n) for n=1..9.

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

Formula

a(n) = 1 + 9*(n-1) for odd n; a(n) = 9*n for even n. Recursion: a(1) = 1; a(2) = 18; a(n+1) = a(n-1) + 18. - (Klaus Brockhaus, Jul 28 2006)

Crossrefs

Records in A118511.

Cf. A117230, A117831, A118473, A118474.

Sequence in context: A095393 A301601 A056022 * A022108 A041654 A041656

Adjacent sequences: A118507 A118508 A118509 * A118511 A118512 A118513

Keyword

nonn,base

Author

N. J. A. Sloane, May 06 2006

Extensions

a(5) to a(9) from Klaus Brockhaus, Jul 28 2006

Status

approved