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A276399 Numerator of n!/(n^n-n). 2
1, 1, 2, 1, 24, 5, 720, 126, 4480, 6048, 3628800, 95040, 479001600, 55598400, 5806080, 1816214400, 20922789888000, 40327372800, 6402373705728000, 2501955993600, 8911728967680000, 193526296104960000, 1124000727777607680000, 696294353018880000, 2256176006302688870400 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

LINKS

Chai Wah Wu, Table of n, a(n) for n = 2..453

Natasha Morrison and Alex Scott, Maximizing the number of induced cycles in a graph, Preprint, 2016. See Conj. 1.1.

EXAMPLE

1, 1/4, 2/21, 1/26, 24/1555, 5/817, 720/299593, 126/134521, 4480/12345679, 6048/43229041, 3628800/67546215517, 95040/4622635937, 479001600/61054982558011, ...

MATHEMATICA

Table[Numerator[n! / (n^n - n)], {n, 2, 30}] (* Vincenzo Librandi, Sep 12 2016 *)

PROG

(Python)

from __future__ import division

from math import factorial

from fractions import gcd

def A276399(n):

    a = factorial(n-1)

    return a//gcd(n**(n-1)-1, a) # Chai Wah Wu, Sep 11 2016

(MAGMA) [Numerator(Factorial(n)/(n^n-n)): n in [2..25]]; // Vincenzo Librandi, Sep 12 2016

CROSSREFS

Cf. A276400.

Sequence in context: A261407 A037943 A073876 * A119828 A328826 A297892

Adjacent sequences:  A276396 A276397 A276398 * A276400 A276401 A276402

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane, Sep 11 2016

STATUS

approved

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Last modified May 31 19:40 EDT 2020. Contains 334748 sequences. (Running on oeis4.)