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A036503 Denominator of n^(n-2)/n!. 7
1, 2, 2, 3, 24, 5, 720, 315, 4480, 567, 3628800, 1925, 479001600, 868725, 14350336, 638512875, 20922789888000, 14889875, 6402373705728000, 14849255421, 7567605760000, 17717861581875, 1124000727777607680000, 2505147019375 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Denominators of coefficient in LambertW(x) power series, where LambertW(x) is the transcendental function satisfying LambertW(x)*exp( LambertW(x) )=x. - Benoit Cloitre, May 08 2002

Absolute value of denominator of the coefficient of 1/(n*x-1) in the partial fraction decomposition of 1/(x-1)*1/(2*x-1)*...*1/(n*x-1). [Joris Roos (jorisr(AT)gmx.de), Aug 02 2009]

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..450

EXAMPLE

1, 1/2, 1/2, 2/3, 25/24, 9/5, 2401/720, 2048/315, 59049/4480, 15625/567, 214358881/3628800, ...

MATHEMATICA

Denominator[Table[n^(n - 2)/n!, {n, 1, 50}]] (* G. C. Greubel, Nov 14 2017 *)

PROG

(PARI) for(n=1, 50, print1(denominator(n^(n-2)/n!), ", ")) \\ G. C. Greubel, Nov 14 2017

(MAGMA) [Denominator(n^(n - 2)/Factorial(n)): n in [1..50]]; // G. C. Greubel, Nov 14 2017

CROSSREFS

Cf. A036502, A036504.

Sequence in context: A084745 A192434 A189254 * A109590 A074935 A320103

Adjacent sequences:  A036500 A036501 A036502 * A036504 A036505 A036506

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified February 25 12:53 EST 2021. Contains 341607 sequences. (Running on oeis4.)