%I #4 Mar 30 2012 18:56:21

%S 1,2,3,4,5,7,1,11,13,15,10,19,2,23,25,12,22,31,3,35,4,14,24,34,45,5,

%T 51,54,57,50,7,8,69,72,75,9,18,1,87,90,11,28,99,102,105,73,13,114,117,

%U 120,76,15,129,132,53,68,17,10,113,128,82,19,20

%N a(n)=least k such that base 5 representation of n begins at s(k), where s=A031219.

%K nonn

%O 1,2

%A _Clark Kimberling_