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 A130071 #6 Feb 20 2022 14:36:17 %S A130071 2,2,1,2,0,3,2,1,0,4,2,0,0,0,9,2,1,3,0,0,7,2,0,0,0,0,0,15,2,1,0,4,0,0, %T A130071 0,12,2,0,3,0,0,0,0,0,18,2,1,0,0,9,0,0,0,0,17 %N A130071 Triangle, A007444(k) in each column interspersed with k zeros. %C A130071 Row sums = the primes. T(n,k) = 0 if k does not divide n. If k divides n, extract A007444(k) which become the nonzero terms of row n, sum = n-th prime. Example: The factors of 6 are (1, 2, 3 and 6) = k's for A007444(k) = (2 + 1 + 3 + 7) = p(6) = 13. A007444 = the Moebius transform of the primes, (2, 1, 3, 4, 9, 7, 15, 12, ...), as the right diagonal of A130071. %F A130071 Given the Moebius transform of the primes, A007444: (2, 1, 3, 4, 9, 7, 15, ...), the k-th term (k= 1,2,3,...) of this sequence generates the k-th column of A130071, interspersed with (k-1) zeros. %e A130071 First few rows of the triangle: %e A130071 2; %e A130071 2, 1; %e A130071 2, 0, 3; %e A130071 2, 1, 0, 4; %e A130071 2, 0, 0, 0, 9; %e A130071 2, 1, 3, 0, 0, 7; %e A130071 2, 0, 0, 0, 0, 0, 15; %e A130071 2, 1, 0, 4, 0, 0, 0, 12; %e A130071 2, 0, 3, 0, 0, 0, 0, 0, 18; %e A130071 2, 1, 0, 0, 9, 0, 0, 0, 0, 17; %e A130071 ... %Y A130071 Cf. A130070, A007444, A054525, A000040. %K A130071 nonn,tabl %O A130071 1,1 %A A130071 _Gary W. Adamson_, May 05 2007