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 A190448 #7 Jun 28 2017 20:29:50 %S A190448 4,9,12,17,20,25,30,33,38,43,46,51,54,59,64,67,72,75,77,80,85,88,93, %T A190448 98,101,106,109,114,119,122,127,132,135,140,143,148,153,156,161,164, %U A190448 166,169,174,177,182,187,190,195,198,203,208,211,216,219,221,224,229,232,237,242,245,250,253,258,263,266,271,276,279,284,287,292 %N A190448 Positions of 2 in A190445. %C A190448 See A190445. %t A190448 (See A190445.) %Y A190448 Cf. A190445. %K A190448 nonn %O A190448 1,1 %A A190448 _Clark Kimberling_, May 10 2011