A031320 - OEIS

%I #4 Mar 30 2012 18:56:23

%S 4,13,23,33,43,53,63,66,68,70,72,73,74,83,93,107,122,137,152,167,182,

%T 197,202,205,208,211,212,214,227,242,257,272,287,302,317,332,347,352,

%U 355,358,361,362,364,377,392,407,422,437,452

%N Position of n-th 7 in A031312.

%K nonn

%O 1,1

%A _Clark Kimberling_