A160618 Denominator of Laguerre(n, -1).

1, 1, 2, 3, 24, 60, 720, 2520, 40320, 25920, 3628800, 19958400, 479001600, 3113510400, 87178291200, 59439744000, 426995712000, 177843714048000, 582033973248000, 60822550204416000, 143111882833920000

Offset: 0

Author

N. J. A. Sloane, Nov 14 2009

Keywords

• nonn
• frac

Links

• G. C. Greubel, Table of n, a(n) for n = 0..449

Crossrefs

For numerators see A160617.

Cf. A002720.

Programs

Magma

[Denominator((&+[Binomial(n,k)*(1/Factorial(k)): k in [0..n]])): n in [0..30]]; // G. C. Greubel, May 06 2018

Mathematica

Denominator[Table[LaguerreL[n, -1], {n, 0, 50}]] (* G. C. Greubel, May 06 2018 *)

PARI

lista(nn) = {x = 'x + O('x^nn); v = exp(x/(1-x))/(1-x); for (n=0, nn-1, print1(denominator(polcoeff(v, n)), ", "););} \\ Michel Marcus, Nov 27 2015

PARI

for(n=0,30, print1(denominator(sum(k=0,n, binomial(n,k)*(1/k!))), ", ")) \\ G. C. Greubel, May 06 2018