A367254 a(n) = binomial(2*n - 1, n - 1)*(2*n)^n.

1, 2, 48, 2160, 143360, 12600000, 1379524608, 180889572864, 27638114549760, 4822114348846080, 945950720000000000, 206098414000597966848, 49378358320648503164928, 12902739286521391316172800, 3651796443284936332620595200, 1112883434275320000000000000000

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Formula

a(n) = abs(A137452(2*n, n)).

a(n) ~ 2^(3*n-1) * n^(n-1/2) / sqrt(Pi). - Amiram Eldar, Sep 18 2025

Maple

a := n -> binomial(2*n - 1, n - 1)*(2*n)^n;
seq(a(n), n = 0..15);

Mathematica

A367254[n_]:=If[n==0, 1, Binomial[2n-1, n-1](2n)^n];
Array[A367254, 20, 0] (* Paolo Xausa, Dec 01 2023 *)

Crossrefs

Cf. A137452.

Sequence in context: A119695 A119698 A112103 * A177317 A114714 A186416

Adjacent sequences: A367251 A367252 A367253 * A367255 A367256 A367257

Keyword

nonn,easy

Author

Peter Luschny, Nov 11 2023

Status

approved