A160612 - OEIS

%I #13 Sep 08 2022 08:45:45

%S 1,1,1,3,3,15,9,315,315,567,14175,6237,467775,6081075,773955,

%T 638512875,9823275,10854718875,7514805375,21837140325,9280784638125,

%U 38979295480125,2143861251406875,3792985290950625,1183411410776595,336196423516078125,9615217712559834375

%N Denominator of Laguerre(n, -4).

%H Alois P. Heinz, <a href="/A160612/b160612.txt">Table of n, a(n) for n = 0..507</a>

%p a:= n-> denom(add(binomial(n, i)*4^i/i!, i=0..n)):

%p seq(a(n), n=0..25);  # _Alois P. Heinz_, Jun 27 2017

%t Denominator[Table[LaguerreL[n, -4], {n, 0, 50}]] (* _G. C. Greubel_, May 12 2018 *)

%o (PARI) for(n=0,30, print1(denominator(sum(k=0,n, binomial(n,k)*(4^k/k!))), ", ")) \\ _G. C. Greubel_, May 12 2018

%o (PARI) a(n) = denominator(pollaguerre(n, 0, -4)); \\ _Michel Marcus_, Feb 05 2021

%o (Magma) [Denominator((&+[Binomial(n,k)*(4^k/Factorial(k)): k in [0..n]])): n in [0..30]]; // _G. C. Greubel_, May 12 2018

%Y For numerators see A160611.

%Y Cf. A289147.

%K nonn,frac

%O 0,4

%A _N. J. A. Sloane_, Nov 14 2009