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 A047145 #4 Mar 30 2012 18:56:53 %S A047145 1,5,19,68,250,935,3473,12850,48066,181540,686960,2600830,9893064, %T A047145 37819055,144917337,556011134,2138565128,8248348136,31873293528, %U A047145 123320614254,477883163716,1855021589250,7210702449848,28058894828756 %N A047145 T(n,n-3), array T as in A047140. %K A047145 nonn %O A047145 3,2 %A A047145 _Clark Kimberling_