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 A049743 #4 Mar 30 2012 18:56:56 %S A049743 29,57,97,145,213,285,373,481,593,709,853,997,1161,1353,1533,1741, %T A049743 1941,2177,2409,2661,2933,3189,3505,3793,4109,4429,4765,5137,5489, %U A049743 5877,6253,6641,7073,7497,7957,8405,8849,9337,9809 %N A049743 a(n)=T(n,n+3), array T as in A049735. %K A049743 nonn %O A049743 0,1 %A A049743 _Clark Kimberling_