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 A143424 #2 Mar 30 2012 17:25:31 %S A143424 1,-1,2,-1,0,4,0,-2,0,8,-1,0,0,0,16,1,-2,-4,0,0,32,-1,0,0,0,0,0,64,0, %T A143424 0,0,-8,0,0,0,128,0,0,-4,0,0,0,0,0,256,1,-2,0,0,-16,0,0,0,0,512,-1,0, %U A143424 0,0,0,0,0,0,0,0,1024,0,2,0,-8,0,-32,0,0,0,0,0,2048 %N A143424 Triangle read by rows, A054525 * A130123, 1<=k<=n. %C A143424 Row sums = A000740 starting with offset 1: (1, 1, 3, 6, 15, 27, 63,...). %C A143424 Left border = mu(n), A008683. %F A143424 Mobius transform of A130123, where A130123 = an infinite lower triangular matrix with (1, 2, 4, 8,...) in the main diagonal and the rest zeros. %e A143424 First few rows of the triangle = %e A143424 1; %e A143424 -1, 2; %e A143424 -1, 0, 4; %e A143424 0, -2, 0, 8; %e A143424 -1, 0, 0, 0, 16; %e A143424 1, -2, -4, 0, 0, 32; %e A143424 -1, 0, 0, 0, 0, 0, 64; %e A143424 0, 0, 0, -8, 0, 0, 0, 128; %e A143424 ... %Y A143424 Cf. A000740, A130123, A054525, A008683. %K A143424 tabl,sign %O A143424 1,3 %A A143424 _Gary W. Adamson_, Aug 14 2008