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 A047147 #4 Mar 30 2012 18:56:53 %S A047147 1,2,5,24,38,96,843,3840,12244,41612,186870,785256,2921302,10834752, %T A047147 43743005,176571744,684645006,2630576822,10387337222,41267967576, %U A047147 161904551038,631554736186,2485459256832,9822930677872,38685615768302 %N A047147 T(n,n+2), array T as in A047140. %K A047147 nonn %O A047147 0,2 %A A047147 _Clark Kimberling_