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 A143718 #3 Mar 30 2012 16:50:59 %S A143718 4,8,16,20,25,28,32,40,44,48,49,50,52,56,64,68,76,80,81,88,92,96,98, %T A143718 100,104,112,116,121,124,125,128,136,140,144,148,152,160,162,164,169, %U A143718 172,175,176,184,188,192,196,200,208,212,220,224,232,236,242,243,244,245,248,250 %N A143718 Complement of A135130. %K A143718 nonn %O A143718 1,1 %A A143718 _N. J. A. Sloane_, Nov 29 2008