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 A126126 #10 Mar 04 2014 01:52:20
%S A126126 1,-1,1,2,-4,1,-5,13,-7,1,13,-40,33,-10,1,-34,120,-132,62,-13,1,89,
%T A126126 -354,483,-308,100,-16,1,-233,1031,-1671,1345,-595,147,-19,1,610,
%U A126126 -2972,5561,-5398,3030,-1020,203,-22,1,-1597,8495,-17984,20410,-13893,5943,-1610,268,-25,1,4181,-24110,56886,-73816,59059,-30702,10570,-2392,342,-28,1
%N A126126 Triangle read by rows: matrix inverse of A110877.
%C A126126 A110877 can be generated from M^n * [1,0,0,0...] where M = an infinite tridiagonal matrix with 1's in the super and subdiagonals and (1,3,3,3...) in the main diagonal.
%C A126126 Up to signs the same as A124037. - _R. J. Mathar_, Sep 06 2013
%C A126126 Riordan array ((1+2*x)/(1+3*x+x^2), x/(1+3*x+x^2)). - _Philippe Deléham_, Mar 04 2014
%F A126126 Sum_{j=k..n} T(n,j)*A110877(j,k) = delta(n,k).
%e A126126 First few rows of the triangle are:
%e A126126 1;
%e A126126 -1, 1;
%e A126126 2, -4, 1;
%e A126126 -5, 13, -7, 1;
%e A126126 13, -40, 33, -10, 1;
%e A126126 -34, 120, -132, 62, -13, 1
%e A126126 ...
%Y A126126 Cf. A110877.
%K A126126 tabl,sign
%O A126126 0,4
%A A126126 _Gary W. Adamson_, Dec 17 2006
%E A126126 Corrected by _R. J. Mathar_, Sep 06 2013