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Number of iterations of x -> x + A064834(x) to reach a palindrome, starting with n (or -1 if no palindrome is ever reached).
3

%I #1 May 16 2003 03:00:00

%S 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,

%T 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,

%U 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

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

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

%e 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

%K base,nonn

%O 1,12

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