This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A138671 #1 Jun 29 2008 03:00:00
%S A138671 2,5,7,8,11,14,16,17,20,22,23,25,26,29,32,34,35,38,41,43,44,47,49,50,
%T A138671 52,53,56,59,61,62,65,67,68,70,71,74,76,77,79,80,83,86,88,89,92,95,97,
%U A138671 98,101,103,104
%N A138671 Indices of 1's in Stewart's choral sequence.
%F A138671 3^{m+1}n+(5(3^m)-1)/2 for m,n in {0,1,2,...}
%Y A138671 Cf. A116178, A138670.
%K A138671 easy,nonn
%O A138671 0,1
%A A138671 Joel Reyes Noche (joel.noche(AT)up.edu.ph), Mar 26 2008