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 A037973 #7 Jul 26 2015 12:03:36 %S A037973 4,8,9,12,14,17,18,22,24,25,28,29,31,35,36,37,38,42,43,44,45,49,51,52, %T A037973 55,56,58,62,63,66,68,71,72,73,74,75,76,77,84,85,86,87,88,89,90,93,95, %U A037973 98,99,103,105,106,109,110,111 %N A037973 Numbers whose maximal base 3 run length is 2. %Y A037973 Cf. A043277. %K A037973 nonn,base %O A037973 1,1 %A A037973 _Clark Kimberling_