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 A091537 #3 Oct 12 2012 14:40:20 %S A091537 1,11,341,19841,1683981,143771891,-15351301839,-27396364105599, %T A091537 -24059921739904039,-21285850978489377989,-20814945866103868804819, %U A091537 -22980130985849165090290239,-28698856680135265507625861339,-40335646598356375740067161474269 %N A091537 Alternating row sums of array A091534 (generalized Stirling2 array (5,2)). %F A091537 a(n)=sum(((-1)^k)*A091534(n, k), k=2..2*n), n>=1. %Y A091537 Cf. A072019 (row sums of A091534). %K A091537 sign,easy %O A091537 1,2 %A A091537 _Wolfdieter Lang_, Jan 23 2004