A369395 AGM transform of the even positive numbers.

0, 4, 432, 61696, 12300000, 3339123264, 1195810789376, 549031054934016, 315439869711260160, 222215334010000000000, 188664842745174745939968, 190234762349632291168321536, 224946256003775354246877765632, 308520390288000443379128425267200, 486093585063330330624000000000000000

Offset

1,2

Comments

See A368366 for the definition of the AGM transform.

Links

Paolo Xausa, Table of n, a(n) for n = 1..210

Mathematica

A369395[n_] := n^n*((n+1)^n - (2*n)!!);
Array[A369395, 15] (* Paolo Xausa, Jan 29 2024 *)

Prog

(PARI) a369395(n) = {my(v=vector(n, i, i+i)); vecsum(v)^n - n^n*vecprod(v)};
(Python)
from math import factorial
def A369395(n): return n**n*((n+1)**n-(factorial(n)<<n))  # Chai Wah Wu, Jan 25 2024

Crossrefs

Cf. A299174, A368366, A368367-A368371, A369394.

Sequence in context: A080321 A360844 A264469 * A172858 A125760 A053780

Adjacent sequences: A369392 A369393 A369394 * A369396 A369397 A369398

Keyword

nonn,easy

Author

Hugo Pfoertner, Jan 24 2024

Status

approved