A100800 Let f(n) = n + sum of the digits of n. If f(n) is multiple of n then a(n)= f(n) else a(n) = f(f(f(n)))... until one gets a multiple of n; a(n) = 0 if no such number exists.
2, 4, 6, 8, 10, 12, 14, 16, 18, 130, 341, 24, 130, 392, 30, 320, 119, 36, 950, 80, 84, 88, 115, 96, 950, 104, 54, 392, 406, 120, 341, 736, 231, 578, 455, 72, 851, 950, 507, 320, 328, 210, 559, 440, 90, 184, 658, 480, 392, 950, 204, 416, 530, 162, 1430, 2128, 114
Offset: 1
Examples
a(10) = 130, f(10) = 10 + 1 = 11, f(f(10)) = f(11) = 13,... we get the sequence 10,11,13,17,25,32,37,47,58,71,79,95,109,119,130,...
Extensions
Extended by Ray Chandler, Dec 19 2004
Comments