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 A026204 #4 Mar 30 2012 18:56:05 %S A026204 2,1,4,8,3,14,5,16,6,20,7,26,9,10,32,11,34,12,38,13,44,15,50,17,52,18, %T A026204 56,19,58,62,21,22,68,23,70,24,74,25,76,80,27,28,86,29,88,30,92,31,98, %U A026204 33,104,35,106,36,110,37,112,116,39,40,122 %N A026204 a(n) = (1/5)*s(n), where s(n) is the n-th multiple of 5 in A026166. %K A026204 nonn %O A026204 1,1 %A A026204 _Clark Kimberling_