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 A128408 #9 Jun 05 2023 04:26:49 %S A128408 1,-1,-1,-1,0,-1,0,0,0,0,-1,0,0,0,-1,1,1,1,0,0,1,-1,0,0,0,0,0,-1,0,0, %T A128408 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,1,0,0,0,0,1,-1,0,0,0,0,0,0,0,0, %U A128408 0,-1,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,0,-1,1,1,0,0,0,0,1,0,0,0,0,0,0,1 %N A128408 Triangle read by rows: A128407 * A051731 as infinite lower triangular matrices. %C A128408 Left and right borders = mu(n), A008683. Row sums = A008966: (1, -2, -2, 0, -2, 4, -2, 0, 0, 4, ...). A128408 * [1,2,3,...] = A063441: (1, -3, -4, 0, -6, 12, ...). A054524 = A051731 * A128407. %e A128408 First few rows of the triangle: %e A128408 1; %e A128408 -1, -1; %e A128408 -1, 0, -1; %e A128408 0, 0, 0, 0; %e A128408 -1, 0, 0, 0, -1; %e A128408 1, 1, 1, 0, 0, 1; %e A128408 ... %Y A128408 Cf. A008683, A008966, A054524, A063441, A128407. %K A128408 tabl,sign %O A128408 1,1 %A A128408 _Gary W. Adamson_, Mar 01 2007 %E A128408 a(45) = 0 inserted and more terms from _Georg Fischer_, Jun 05 2023