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 A384692 #9 Jun 07 2025 08:21:30 %S A384692 1,1,0,1,1,0,1,2,7,0,1,3,16,112,0,1,4,27,266,2989,0,1,5,40,468,7168, %T A384692 115136,0,1,6,55,724,12789,275842,5899159,0,1,7,72,1040,20128,493248, %U A384692 14058520,381657928,0,1,8,91,1422,29485,780164,25060203,903187826,30082660633,0 %N A384692 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of e.g.f. B(x)^k, where B(x) is the e.g.f. of A384691. %F A384692 A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} (n+k)^(j-1) * binomial(n,j) * A(n-j,2*j). %e A384692 Square array begins: %e A384692 1, 1, 1, 1, 1, 1, ... %e A384692 0, 1, 2, 3, 4, 5, ... %e A384692 0, 7, 16, 27, 40, 55, ... %e A384692 0, 112, 266, 468, 724, 1040, ... %e A384692 0, 2989, 7168, 12789, 20128, 29485, ... %e A384692 0, 115136, 275842, 493248, 780164, 1151200, ... %o A384692 (PARI) a(n, k) = if(k==0, 0^n, k*sum(j=0, n, (n+k)^(j-1)*binomial(n, j)*a(n-j, 2*j))); %Y A384692 Columns k=0..1 give A000007, A384691. %K A384692 nonn,tabl %O A384692 0,8 %A A384692 _Seiichi Manyama_, Jun 07 2025