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 A114157 #5 Jun 13 2017 23:40:26 %S A114157 1,-1,3,6,-8,-501,-13623,-409953,-14544683,-607055209,-29421219966, %T A114157 -1632715832341,-102423931253271,-7182065357683744, %U A114157 -557479490745141406,-47499193522110824640,-4410100445892863617679,-443346294340660384160358 %N A114157 Column 0 of triangle A114156, which is the matrix inverse of A113370. %o A114157 (PARI) a(n)=local(P,Q,R,W);P=Mat(1);for(m=2,n+1,W=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,W[i,j]=1,if(j==1, W[i,1]=1,W[i,j]=(P^(3*j-2))[i-j+1,1]));));P=W); (P^-1)[n+1,1] %Y A114157 Cf. A114156, A113370. %K A114157 sign %O A114157 0,3 %A A114157 _Paul D. Hanna_, Nov 15 2005