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 A049742 #4 Mar 30 2012 18:56:56 %S A049742 13,37,69,109,169,241,317,421,517,641,769,917,1085,1237,1433,1617, %T A049742 1829,2053,2261,2537,2785,3061,3333,3613,3945,4257,4597,4941,5281, %U A049742 5673,6041,6461,6861,7289,7713,8129,8613,9085,9577 %N A049742 a(n)=T(n,n+2), array T as in A049735. %K A049742 nonn %O A049742 0,1 %A A049742 _Clark Kimberling_