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 A091758 #3 Oct 12 2012 14:40:20 %S A091758 1,41,5993,1911281,1070544561,931648129241,1164230224629081, %T A091758 1977455909783346273,4384042247054153832161, %U A091758 12298460017360155919009801,42594621493418383255115778761,178534870708446720311905067877201,890813416549297707507952795640859793 %N A091758 Alternating row sums of array A092077 ((8,2)-Stirling2). %C A091758 The first negative member is the 680 digit number a(138)=-2266379480...2912329207. %F A091758 a(n)= sum( A092077(n, k)*(-1)^k, k=2..2*n), n>=1. %Y A091758 Cf. A091757 (row sums of A092077). %K A091758 sign,easy %O A091758 1,2 %A A091758 _Wolfdieter Lang_, Feb 27 2004