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 A049730 #4 Mar 30 2012 18:56:56 %S A049730 9,22,39,60,92,129,169,222,271,335,400,476,561,638,738,831,939,1052, %T A049730 1157,1297,1422,1562,1699,1840,2008,2165,2337,2510,2682,2879,3064, %U A049730 3276,3477,3693,3906,4115,4359,4596,4844,5085,5337 %N A049730 a(n)=T(n,n+2), array T as in A049723. %K A049730 nonn %O A049730 0,1 %A A049730 _Clark Kimberling_