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 A026245 #4 Mar 30 2012 18:56:05 %S A026245 1,3,4,2,7,8,12,5,6,16,20,21,9,24,25,10,11,29,33,13,14,37,38,15,41,42, %T A026245 17,45,46,18,19,50,54,55,22,58,59,23,62,63,67,26,27,71,72,28,75,76,30, %U A026245 79,80,31,32,84,88,34,35,92,93,36,96,97,101 %N A026245 a(n) = (1/2)*(s(n) + 1), where s(n) is the n-th odd number in A002251. %K A026245 nonn %O A026245 1,2 %A A026245 _Clark Kimberling_