A369018 Triangle read by rows: T(n, k) = binomial(n, k - 1)*(k - 1)^(k - 1)*n*(n - k + 1)^(n - k).

0, 0, 1, 0, 4, 4, 0, 27, 18, 36, 0, 256, 144, 192, 432, 0, 3125, 1600, 1800, 2700, 6400, 0, 46656, 22500, 23040, 29160, 46080, 112500, 0, 823543, 381024, 367500, 423360, 564480, 918750, 2286144, 0, 16777216, 7529536, 6967296, 7560000, 9175040, 12600000, 20901888, 52706752

Offset

0,5

Links

Table of n, a(n) for n=0..44.

Formula

T = A368849 + A369019.

Example

Triangle read by rows:
[0] [0]
[1] [0,      1]
[2] [0,      4,      4]
[3] [0,     27,     18,     36]
[4] [0,    256,    144,    192,    432]
[5] [0,   3125,   1600,   1800,   2700,   6400]
[6] [0,  46656,  22500,  23040,  29160,  46080, 112500]
[7] [0, 823543, 381024, 367500, 423360, 564480, 918750, 2286144]

Maple

T := (n, k) -> binomial(n, k - 1)*(k - 1)^(k - 1)*n*(n - k + 1)^(n - k):
seq(seq(T(n, k), k = 0..n), n=0..9);

Mathematica

A369018[n_, k_] := Binomial[n, k-1] If[k == 1, 1, (k-1)^(k-1)] n (n-k+1)^(n-k);
Table[A369018[n, k], {n, 0, 10}, {k, 0, n}] (* Paolo Xausa, Jan 27 2024 *)

Prog

(SageMath)
def A369018(n, k):
    return binomial(n, k - 1)*(k - 1)^(k - 1)*n*(n - k + 1)^(n - k)

Crossrefs

Cf. A369019, A368849.

Sequence in context: A205507 A137862 A006805 * A030045 A371049 A126089

Adjacent sequences: A369015 A369016 A369017 * A369019 A369020 A369021

Keyword

nonn,tabl

Author

Peter Luschny, Jan 13 2024

Status

approved