A064844 Number of iterations of x -> x + A064834(x) to reach a palindrome, starting with n (or -1 if no palindrome is ever reached).

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 6, 5, 6, 4, 2, 5, 7, 3, 1, 1, 0, 4, 3, 6, 2, 2, 5, 7, 1, 1, 1, 0, 4, 3, 6, 2, 2, 5, 1, 1, 1, 1, 0, 4, 3, 2, 2, 2, 1, 1, 1, 1, 1, 0, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 0, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 0, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 0, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1

Offset

1,12

Comments

Longest sequence for n<252784 is a(250584)=2311. Is a palindromic number always reached?

Links

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

Example

For n=16, A064834(16) = 5, so next number is 16+5 = 21. A064834(21)=1 so next number is 22. 22 is a palindrome which is reached after 2 iterations, so a(16)=2

Crossrefs

Sequence in context: A231738 A198829 A217170 * A242723 A111718 A106154

Adjacent sequences: A064841 A064842 A064843 * A064845 A064846 A064847

Keyword

base,nonn

Author

Jonathan Ayres (jonathan.ayres(AT)btinternet.com), Oct 25 2001

Status

approved