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 A190709 #4 Mar 30 2012 18:57:29 %S A190709 4,15,19,30,34,45,56,60,71,75,86,90,101,112,116,127,131,142,157,168, %T A190709 172,183,187,198,209,213,224,228,239,243,254,265,269,280,284,295,310, %U A190709 321,325,336,340,351,366,377,381,392,396,407,418,422,433,437,448,452,463,474,478,489,493,504,519,530,534,545,549,560,575,586,590 %N A190709 Positions of 4 in A190704. %C A190709 See A190704. %t A190709 (See A190704.) %Y A190709 Cf. A190704. %K A190709 nonn %O A190709 1,1 %A A190709 _Clark Kimberling_, May 17 2011