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.

A370706 Triangle read by rows: T(n, k) = binomial(n, k) * Pochhammer(n, k).

Original entry on oeis.org

1, 1, 1, 1, 4, 6, 1, 9, 36, 60, 1, 16, 120, 480, 840, 1, 25, 300, 2100, 8400, 15120, 1, 36, 630, 6720, 45360, 181440, 332640, 1, 49, 1176, 17640, 176400, 1164240, 4656960, 8648640, 1, 64, 2016, 40320, 554400, 5322240, 34594560, 138378240, 259459200
Offset: 0

Views

Author

Peter Luschny, Feb 28 2024

Keywords

Examples

			Triangle starts:
  [0] 1;
  [1] 1,  1;
  [2] 1,  4,    6;
  [3] 1,  9,   36,    60;
  [4] 1, 16,  120,   480,    840;
  [5] 1, 25,  300,  2100,   8400,   15120;
  [6] 1, 36,  630,  6720,  45360,  181440,  332640;
  [7] 1, 49, 1176, 17640, 176400, 1164240, 4656960, 8648640;
		

Crossrefs

Cf. A370707, A000407 (main diagonal), A278070 (row sums).

Programs

  • Maple
    T := (n, k) -> binomial(n, k)*pochhammer(n, k):
    seq(seq(T(n, k), k = 0..n), n = 0..8);
  • Mathematica
    T[n_, k_] := Binomial[n, k] Pochhammer[n, k];
    Table[T[n, k], {n, 0, 8}, {k, 0, n}] // Flatten

Formula

T(n, k) = A370707(n, k) / k!.
T(n, n) = Pochhammer(n, n) for n >= 0 (which is different from A000407(n)).