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 A259428 #5 Jun 28 2015 03:34:57 %S A259428 1,2,3,11,27,35,51,53,79,83,89,93,117,123,125,135,143,145,161,171,173, %T A259428 177,179,189,197,203,205,215,219,223,233,237,249,251,255,263,267,277, %U A259428 287,291,293,297,303,305,321,341,343,345,353,359,363,371,373,377,383,395,407 %N A259428 Numbers never appearing in A259124. %Y A259428 Cf. A259124. %K A259428 nonn %O A259428 1,2 %A A259428 _Alex Ratushnyak_, Jun 26 2015