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 A134700 #15 Apr 30 2025 09:11:03 %S A134700 1,3,1,5,1,1,8,3,1,1,10,3,1,1,1,14,5,3,1,1,1,16,5,3,1,1,1,1,20,8,3,3, %T A134700 1,1,1,1,23,8,5,3,1,1,1,1,1,27,10,5,3,3,1,1,1,1,1,29,10,5,3,3,1,1,1,1, %U A134700 1,1,35,14,8,5,3,3,1,1,1,1,1,1,37,14,8,5,3,3,1,1,1,1,1,1,1 %N A134700 Triangle read by rows: A000012 * A051731^2. %C A134700 Left column = A006218. %C A134700 Row sums = A061201: (1, 4, 7, 13, 16, 25, 28, ...). %C A134700 A134699 = A127170 * A000012. %F A134700 A000012 * A051731^2 = A000012 * A127170. %e A134700 First few rows of the triangle: %e A134700 1; %e A134700 3, 1; %e A134700 5, 1, 1; %e A134700 8, 3, 1, 1; %e A134700 10, 3, 1, 1, 1; %e A134700 14, 5, 3, 1, 1, 1; %e A134700 16, 5, 3, 1, 1, 1, 1; %e A134700 20, 8, 3, 3, 1, 1, 1, 1; %e A134700 23, 8, 5, 3, 1, 1, 1, 1, 1; %e A134700 ... %o A134700 (PARI) row(n) = my(m=matrix(n,n,i,j,!(i%j))); vector(n, k, sum(i=1, n, (m^2)[i, k])); \\ _Michel Marcus_, Apr 30 2025 %Y A134700 Cf. A006218, A051731, A061201, A127170, A134699. %K A134700 nonn,tabl %O A134700 1,2 %A A134700 _Gary W. Adamson_, Nov 07 2007 %E A134700 a(45) = 1, a(46) = 27 corrected and more terms from _Georg Fischer_, Jun 05 2023 %E A134700 More terms from _Michel Marcus_, Apr 30 2025