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.

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A362788 Triangle read by rows, T(n, k) = RisingFactorial(n - k, k) * Stirling2(n - k, k), for n >= 0 and 0 <= k <= n//2, where '//' denotes integer division.

Original entry on oeis.org

1, 0, 0, 1, 0, 2, 0, 3, 6, 0, 4, 36, 0, 5, 140, 60, 0, 6, 450, 720, 0, 7, 1302, 5250, 840, 0, 8, 3528, 30240, 16800, 0, 9, 9144, 151704, 196560, 15120, 0, 10, 22950, 695520, 1764000, 453600, 0, 11, 56210, 2994750, 13471920, 7761600, 332640
Offset: 0

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Author

Peter Luschny, May 04 2023

Keywords

Examples

			Triangle T(n, k) starts:
[0] 1;
[1] 0;
[2] 0, 1;
[3] 0, 2;
[4] 0, 3,    6;
[5] 0, 4,   36;
[6] 0, 5,  140,    60;
[7] 0, 6,  450,   720;
[8] 0, 7, 1302,  5250,   840;
[9] 0, 8, 3528, 30240, 16800;
		

Crossrefs

Cf. A052512 (row sums), A362369, A362789.

Programs

  • Maple
    T := (n, k) -> pochhammer(n - k, k) * Stirling2(n - k, k):
    seq(seq(T(n, k), k = 0..iquo(n,2)), n = 0..12);
  • SageMath
    def A362788(n, k):
        return rising_factorial(n - k, k) * stirling_number2(n - k, k)
    for n in range(10):
        print([A362788(n, k) for k in range(n//2 + 1)])
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