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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.

A373426 Triangle read by rows: Coefficients of the polynomials L(n, x) * EZ(n, x), where L denote the unsigned Lah polynomials and EZ the Eulerian zig-zag polynomials A205497.

Original entry on oeis.org

1, 0, 1, 0, 2, 1, 0, 6, 12, 7, 1, 0, 24, 108, 144, 73, 15, 1, 0, 120, 1080, 2640, 2660, 1221, 267, 27, 1, 0, 720, 11880, 48720, 82980, 67350, 28321, 6344, 751, 44, 1, 0, 5040, 146160, 955080, 2529240, 3262350, 2245782, 870283, 195074, 25267, 1831, 68, 1
Offset: 0

Views

Author

Peter Luschny, Jun 07 2024

Keywords

Examples

			Tracing the computation:
  0: [1] *       [1] =                [1]
  1: [1] *       [0,  1] =            [0,  1]
  2: [1] *       [0,  2,  1] =        [0,  2,   1]
  3: [1, 1] *    [0,  6,  6,  1] =    [0,  6,  12,   7,  1]
  4: [1, 3, 1] * [0, 24, 36, 12, 1] = [0, 24, 108, 144, 73, 15, 1]
		

Crossrefs

Cf. A271703 (Lah), A205497 (zig-zag Eulerian), A373425 (row sums).

Programs

  • Maple
    # Using function EZP from A373432.
    EZP((n, k) -> ifelse(n=k, 1, binomial(n-1, k-1)*n!/k!), 7);