%I #9 May 14 2019 11:12:00
%S 1,3,4,6,9,12,13,15,16,19,21,22,24,27,28,30,31,33,36,39,40,42,45,47,
%T 48,50,51,54,57,58,60,63,66,67,69,70,72,75,77,78,81,84,85,87,90,93,94,
%U 96,97,100,102,103,105,108,111,112,114,115,117,120,121,123,124
%N Index of n-th 1 in A006928.
%C a(n) = A013947(n)-1 for n > 1.
%Y Cf. A006928, A013947.
%K nonn
%O 1,2
%A _Clark Kimberling_
%E Offset changed to 1 by _Sean A. Irvine_, May 14 2019