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 A143469 #6 Aug 14 2023 06:54:04 %S A143469 1,4,-1,9,-1,-1,16,-4,-1,0,25,-4,-1,0,-1,36,-9,-4,0,-1,1,49,-9,-4,0, %T A143469 -1,1,-1,64,-16,-4,0,-1,1,-1,0,81,-16,-9,0,-1,1,-1,0,0,100,-25,-9,0, %U A143469 -4,1,-1,0,0,1,121,-25,-9,0,-4,1,-1,0,0,1,-1,144,-36,-16,0,-4,4,-1,0,0,1,-1,0 %N A143469 Triangle read by rows, A000012 * A143315 * A128407, 1<=k<=1. %C A143469 Row sums = A018805: (1, 3, 7, 11, 19, 23, 35,...). %C A143469 Right border = mu(n), A008683. %e A143469 First few rows of the triangle = %e A143469 1; %e A143469 4, -1; %e A143469 9, -1, -1; %e A143469 16, -4, -1, 0; %e A143469 25, -4, -1, 0, -1; %e A143469 36, -9, -4, 0, -1, 1; %e A143469 49, -9, -4, 0, -1, 1, -1; %e A143469 ... %Y A143469 Cf. A008683, A018805, A128407, A143315. %K A143469 tabl,sign %O A143469 1,2 %A A143469 _Gary W. Adamson_, Aug 17 2008 %E A143469 a(9) corrected and more terms from _Georg Fischer_, Aug 14 2023