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 A363007 #18 May 12 2023 16:27:06 %S A363007 1,1,1,1,1,2,1,1,3,6,1,1,4,13,24,1,1,5,23,75,120,1,1,6,36,175,541,720, %T A363007 1,1,7,52,342,1662,4683,5040,1,1,8,71,594,4048,18937,47293,40320,1,1, %U A363007 9,93,949,8444,57437,251729,545835,362880,1,1,10,118,1425,15775,143783,950512,3824282,7087261,3628800 %N A363007 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. 1/(1 - f^k(x)), where f(x) = exp(x) - 1. %F A363007 T(n,k) = Sum_{j=0..n} Stirling2(n,j) * T(j,k-1), k>1, T(n,0) = n!. %F A363007 T(n,k) = A153278(k,n) for n >= 1 and k >= 1. %e A363007 Square array begins: %e A363007 1, 1, 1, 1, 1, 1, ... %e A363007 1, 1, 1, 1, 1, 1, ... %e A363007 2, 3, 4, 5, 6, 7, ... %e A363007 6, 13, 23, 36, 52, 71, ... %e A363007 24, 75, 175, 342, 594, 949, ... %e A363007 120, 541, 1662, 4048, 8444, 15775, ... %o A363007 (PARI) T(n, k) = if(k==0, n!, sum(j=0, n, stirling(n, j, 2)*T(j, k-1))); %Y A363007 Columns k=0..5 give A000142, A000670, A083355, A099391, A363008, A363009. %Y A363007 Main diagonal gives A363010. %Y A363007 Cf. A153278, A351420, A351429. %K A363007 nonn,tabl %O A363007 0,6 %A A363007 _Seiichi Manyama_, May 12 2023