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 A074134 #4 Dec 05 2013 19:55:33 %S A074134 1,2,3,6,10,15,22,29,36,45,55,66,78,91,105,120,136,153,171,190,210, %T A074134 231,253,276,301,326,351,378,406,435,465,496,528,561,595,630,666,703, %U A074134 741,780,820,861,903,946,990,1035,1081,1128,1176,1225,1275,1326,1378,1431 %N A074134 First column of triangle A074135. %Y A074134 Cf. A074135. %K A074134 nonn,easy,less %O A074134 1,2 %A A074134 _Amarnath Murthy_, Aug 27 2002 %E A074134 Edited and extended by _David Wasserman_, Oct 31 2006