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 A051525 #11 Jul 07 2015 21:25:52 %S A051525 0,0,1,21,335,5000,74524,1139292,18083484,299705400,5198985576, %T A051525 94461323616,1797180658272,35776357096896,744402741205824, %U A051525 16169795109262080,366214212167489280,8636605663418933760 %N A051525 Third unsigned column of triangle A051338. %C A051525 From _Johannes W. Meijer_, Oct 20 2009: (Start) %C A051525 The asymptotic expansion of the higher order exponential integral E(x,m=3,n=6) ~ exp(-x)/x^3*(1 - 21/x + 335/x^2 - 5000/x^3 + 74524/x^4 - 1139292/x^5 + ...) leads to the sequence given above. See A163931 and A163932 for more information. %C A051525 (End) %D A051525 Mitrinovic, D. S. and Mitrinovic, R. S. see reference given for triangle A051338. %F A051525 a(n) = A051338(n, 2)*(-1)^n; e.g.f.: (log(1-x))^2/(2*(1-x)^6). %F A051525 If we define f(n,i,a)=sum(binomial(n,k)*stirling1(n-k,i)*product(-a-j,j=0..k-1),k=0..n-i), then a(n) = |f(n,2,6)|, for n>=1. - _Milan Janjic_, Dec 21 2008 %Y A051525 Cf. A001725 (m=0), A051524 (m=1) unsigned columns. %K A051525 easy,nonn %O A051525 0,4 %A A051525 _Wolfdieter Lang_