A160612 Denominator of Laguerre(n, -4).

1, 1, 1, 3, 3, 15, 9, 315, 315, 567, 14175, 6237, 467775, 6081075, 773955, 638512875, 9823275, 10854718875, 7514805375, 21837140325, 9280784638125, 38979295480125, 2143861251406875, 3792985290950625, 1183411410776595, 336196423516078125, 9615217712559834375

Offset: 0

Author

N. J. A. Sloane, Nov 14 2009

Keywords

• nonn
• frac

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..507

Crossrefs

For numerators see A160611.

Cf. A289147.

Programs

Magma

[Denominator((&+[Binomial(n,k)*(4^k/Factorial(k)): k in [0..n]])): n in [0..30]]; // G. C. Greubel, May 12 2018

Maple

a:= n-> denom(add(binomial(n, i)*4^i/i!, i=0..n)):
seq(a(n), n=0..25);  # Alois P. Heinz, Jun 27 2017

Mathematica

Denominator[Table[LaguerreL[n, -4], {n, 0, 50}]] (* G. C. Greubel, May 12 2018 *)

PARI

for(n=0,30, print1(denominator(sum(k=0,n, binomial(n,k)*(4^k/k!))), ", ")) \\ G. C. Greubel, May 12 2018

PARI

a(n) = denominator(pollaguerre(n, 0, -4)); \\ Michel Marcus, Feb 05 2021