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.
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
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]
Links
- Peter Luschny, Illustrating the polynomials.
Programs
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Maple
# Using function EZP from A373432. EZP((n, k) -> ifelse(n=k, 1, binomial(n-1, k-1)*n!/k!), 7);