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 A027997 #5 Mar 30 2012 18:56:16
%S A027997 16,70,292,1197,4864,19656,79124,317592,1271976,5085730,20307396,
%T A027997 81003583,322847552,1285900570,5119076236,20370229878,81032093192,
%U A027997 322258628220,1281334227276,5093898416278,20248096412336,80478051058480
%N A027997 Sum{T(n,k)*T(n,k+3)}, 0<=k<=2n-3, T given by A027926.
%K A027997 nonn
%O A027997 3,1
%A A027997 _Clark Kimberling_