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 A144221 #5 Jun 02 2025 00:34:48 %S A144221 1,-1,-1,1,1,-1,-1,5,-1,1,5,-11,1,1,1,9,-11,-11,9,-1,-1,-9,-9,51,-29, %T A144221 1,1,-1,-1,-57,111,-29,-29,13,-1,1,-15,113,-111,-111,169,-55,1,1,1, %U A144221 -31,113,113,-559,449,-55,-55,17,-1 %N A144221 Triangle read by rows, A118433 * A007318^(-1) * A000012. %C A144221 Row sums = (1, 0, 1, 2, -3, -4, 5, 6, -7, -8,...). %F A144221 Triangle read by rows, A118433 * A007318^(-1) * A000012. %F A144221 A118433 = the self-inverse triangle. A007318^(-1) = the inverse of Pascal's triangle and A000012 = an infinite lower triangular matrix with all 1's. %e A144221 First few rows of the triangle = %e A144221 1; %e A144221 1, -1; %e A144221 -1, 1, 1; %e A144221 -1, -1, 5, -1; %e A144221 1, 5, -11, 1, 1; %e A144221 1, 9, -11, -11, 9, -1; %e A144221 -1, -9, -9, 51, -29, 1, 1 %e A144221 -1, -1, -57, 111, -29, -29, 13, -1; %e A144221 1, -15, 113, -111, -111, 169, -55, 1, 1; %e A144221 ... %Y A144221 A118433 %K A144221 tabl,sign %O A144221 0,8 %A A144221 _Gary W. Adamson_, Sep 14 2008