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 A384788 #11 Jun 10 2025 13:57:10 %S A384788 1,1,0,1,1,0,1,2,7,0,1,3,16,148,0,1,4,27,338,7381,0,1,5,40,576,16240, %T A384788 801536,0,1,6,55,868,26829,1697602,186678019,0,1,7,72,1220,39424, %U A384788 2701488,384962560,93865986880,0,1,8,91,1638,54325,3828164,595921743,190657584770,102755888482153,0 %N A384788 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 A384787. %F A384788 A(n,0) = 0^n; A(n,k) = k * Sum_{j=0..n} 2^(n-j) * (n+k)^(j-1) * binomial(n,j) * A(n-j,j). %e A384788 Square array begins: %e A384788 1, 1, 1, 1, 1, 1, ... %e A384788 0, 1, 2, 3, 4, 5, ... %e A384788 0, 7, 16, 27, 40, 55, ... %e A384788 0, 148, 338, 576, 868, 1220, ... %e A384788 0, 7381, 16240, 26829, 39424, 54325, ... %e A384788 0, 801536, 1697602, 2701488, 3828164, 5094400, ... %o A384788 (PARI) a(n, k) = if(k==0, 0^n, k*sum(j=0, n, 2^(n-j)*(n+k)^(j-1)*binomial(n, j)*a(n-j, j))); %Y A384788 Columns k=0..1 give A000007, A384787. %Y A384788 Cf. A379168. %K A384788 nonn,tabl %O A384788 0,8 %A A384788 _Seiichi Manyama_, Jun 10 2025