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 A143468 #2 Mar 30 2012 17:25:32 %S A143468 1,-1,3,-1,0,5,0,-3,0,7,-1,0,0,0,9,1,-3,-5,0,0,11,-1,0,0,0,0,0,13,0,0, %T A143468 0,-7,0,0,0,15,0,0,-5,0,0,0,0,0,17,1,-3,0,0,-9,0,0,0,0,19,-1,0,0,0,0, %U A143468 0,0,0,0,0,21 %N A143468 Triangle read by rows, A054525 * A127775, 1<=k<=n. %C A143468 Row sums = A140434: (1, 2, 4, 4, 8, 4, 12, 8, 12,...). %C A143468 Left border = mu(n), A008683. %F A143468 Triangle read by rows, A054525 * A127775, 1<=k<=n. Mobius transform of an infinite lower triangular matrix with (1, 3, 5, 7,...) in the main diagonal and the rest zeros. %e A143468 First few rows of the triangle = %e A143468 1; %e A143468 -1, 3; %e A143468 -1, 0, 5; %e A143468 0, -3, 0, 7; %e A143468 -1, 0, 0, 0, 9; %e A143468 1, -3, -5, 0, 0, 11; %e A143468 -1, 0, 0, 0, 0, 0, 13; %e A143468 ... %Y A143468 Cf. A127775, A054525, A140434, A008683. %K A143468 tabl,sign %O A143468 1,3 %A A143468 _Gary W. Adamson_, Aug 17 2008