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.

Showing 1-1 of 1 results.

A350266 Triangle read by rows. T(n, k) = binomial(n, k) * n! / (n - k + 1)! if k >= 1, if k = 0 then T(n, k) = k^n. T(n, k) for 0 <= k <= n.

Original entry on oeis.org

1, 0, 1, 0, 2, 2, 0, 3, 9, 6, 0, 4, 24, 48, 24, 0, 5, 50, 200, 300, 120, 0, 6, 90, 600, 1800, 2160, 720, 0, 7, 147, 1470, 7350, 17640, 17640, 5040, 0, 8, 224, 3136, 23520, 94080, 188160, 161280, 40320, 0, 9, 324, 6048, 63504, 381024, 1270080, 2177280, 1632960, 362880
Offset: 0

Views

Author

Peter Luschny, Jan 09 2022

Keywords

Examples

			Table starts:
[0] 1;
[1] 0, 1;
[2] 0, 2,   2;
[3] 0, 3,   9,    6;
[4] 0, 4,  24,   48,    24;
[5] 0, 5,  50,  200,   300,    120;
[6] 0, 6,  90,  600,  1800,   2160,     720;
[7] 0, 7, 147, 1470,  7350,  17640,   17640,    5040;
[8] 0, 8, 224, 3136, 23520,  94080,  188160,  161280,   40320;
[9] 0, 9, 324, 6048, 63504, 381024, 1270080, 2177280, 1632960, 362880;
		

Crossrefs

A350267 (row sums), A000142 (main diagonal), A074143 (subdiagonal), A006002 (column 2), A089835 (central terms).

Programs

  • Maple
    T := (n, k) -> ifelse(k = 0, k^n, binomial(n, k)^2 * k! / (n - k + 1)):
    seq(seq(T(n, k), k = 0..n), n = 0..9);
  • Mathematica
    T[n_, 0] := Boole[n == 0]; T[n_, k_] := Binomial[n, k]^2 * k!/(n - k + 1); Table[T[n, k], {n, 0, 9}, {k, 0, n}] // Flatten (* Amiram Eldar, Jan 09 2022 *)

Formula

T(n, k) = binomial(n, k)^2 * k! / (n - k + 1) if k >= 1.
Showing 1-1 of 1 results.