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 A027160 #4 Mar 30 2012 18:56:14 %S A027160 5,21,176,680,5808,21840,190976,708480,6310400,23220736,209756160, %T A027160 767676416,7010676736,25558732800,235443322880,855858053120, %U A027160 7939647995904,28796047982592,268690773770240,972740537352192,9120760620646400 %N A027160 a(n) = T(2n,n-2), T given by A027157. %K A027160 nonn %O A027160 2,1 %A A027160 _Clark Kimberling_