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 A134530 #3 Mar 30 2012 18:37:07 %S A134530 0,1,0,-1,4,0,5,-12,12,0,-79,160,-96,32,0,3377,-6320,3200,-640,80,0, %T A134530 -362431,648384,-303360,51200,-3840,192,0,93473345,-162369088, %U A134530 72619008,-11325440,716800,-21504,448,0,-56272471039,95716705280,-41566486528,6196822016,-362414080,9175040,-114688,1024,0 %N A134530 Matrix log of triangle A111636, where A111636(n,k) = (2^k)^(n-k)*C(n,k) for n>=k>=0. %F A134530 T(n,k) = A134531(n-k)*(2^k)^(n-k)*C(n,k), where A134531 is column 0 and satisfies: G.f.: Sum_{n>=0} A134531(n)*x^n/[n!*2^(n*(n-1)/2)] = log(Sum_{n>=0}x^n/[n!*2^(n*(n-1)/2)]). %e A134530 Triangle begins: %e A134530 0, %e A134530 1, 0; %e A134530 -1, 4, 0; %e A134530 5, -12, 12, 0; %e A134530 -79, 160, -96, 32, 0; %e A134530 3377, -6320, 3200, -640, 80, 0; %e A134530 -362431, 648384, -303360, 51200, -3840, 192, 0; %e A134530 93473345, -162369088, 72619008, -11325440, 716800, -21504, 448, 0; ... %e A134530 Matrix exponentiation yields triangle A111636, which begins: %e A134530 1; %e A134530 1, 1; %e A134530 1, 4, 1; %e A134530 1, 12, 12, 1; %e A134530 1, 32, 96, 32, 1; %e A134530 1, 80, 640, 640, 80, 1; ... %o A134530 (PARI) {T(n,k)=local(M=matrix(n+1,n+1,r,c,if(r>=c,2^((c-1)*(r-c))*binomial(r-1,c-1))),L); L=sum(i=1,#M,-(M^0-M)^i/i);L[n+1,k+1]} %Y A134530 Cf. A134531 (column 0); related triangles: A111636, A117401; A011266. %K A134530 sign,tabl %O A134530 0,5 %A A134530 _Paul D. Hanna_, Oct 30 2007