cp's OEIS Frontend

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.

A372311 Triangle read by rows: T(n, k) = n^k * Sum_{j=0..n} binomial(n - j, n - k) * Eulerian1(n, j).

Original entry on oeis.org

1, 1, 1, 1, 6, 8, 1, 21, 108, 162, 1, 60, 800, 3840, 6144, 1, 155, 4500, 48750, 225000, 375000, 1, 378, 21672, 453600, 4354560, 19595520, 33592320, 1, 889, 94668, 3500658, 60505200, 536479440, 2371803840, 4150656720
Offset: 0

Views

Author

Peter Luschny, Apr 26 2024

Keywords

Examples

			Triangle begins:
  [0] 1;
  [1] 1,   1;
  [2] 1,   6,     8;
  [3] 1,  21,   108,     162;
  [4] 1,  60,   800,    3840,     6144;
  [5] 1, 155,  4500,   48750,   225000,    375000;
  [6] 1, 378, 21672,  453600,  4354560,  19595520,   33592320;
  [7] 1, 889, 94668, 3500658, 60505200, 536479440, 2371803840, 4150656720;
		

Crossrefs

Cf. A061711 (main diagonal), A066524 (column 1), A372312 (row sums).
Cf. A163626, A173018 (eulerian1).

Programs

  • Maple
    S := (n, k) -> local j; add(eulerian1(n, j)*binomial(n-j, n-k), j = 0..n):
    row := n -> local k; seq(S(n, k) * n^k, k = 0..n):
    seq(row(n), n = 0..8);
  • SageMath
    def A372311_row(n) :
        x = polygen(ZZ, 'x')
        A = []
        for m in range(0, n + 1, 1) :
            A.append((-x)^m)
            for j in range(m, 0, -1):
                A[j - 1] = j * (A[j - 1] - A[j])
        return [n^k*c for k, c in enumerate(A[0])]
    for n in (0..7) : print(A372311_row(n))