%I #5 Mar 30 2012 18:35:25
%S 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,1,2,
%T 3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,2,3,4,
%U 5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,3,4,5,6,7,8,9,10
%N a(0) = 0; a(n) = a(n/5)/5 if n = a(n/5) = 0 (mod 5); a(n) = a(n-1)+1 otherwise.
%K nonn
%O 0,3
%A _David W. Wilson_
%E Bounded, conjectured maximum is a(3169) = 49.