OFFSET
0,2
COMMENTS
See A129462 for the M. Bruschi et al. reference.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..250
FORMULA
a(n) = A129462(n+1,1), n >= 0.
a(n) = -(n-1)!^2*n*(n+1), n > 0. - Peter Luschny, Oct 15 2010
From Amiram Eldar, May 17 2022: (Start)
Sum_{n>=1} 1/a(n) = -BesselI(2, 2) = -A229020.
Sum_{n>=1} (-1)^n/a(n) = BesselJ(2, 2). (End)
MAPLE
A129464 := n -> `if`(n=0, 1, -(n-1)!^2*n*(n+1)); # Peter Luschny, Oct 15 2010
MATHEMATICA
Table[If[n==0, 1, -(n-1)!*(n+1)!], {n, 0, 30}] (* G. C. Greubel, Feb 08 2024 *)
PROG
(Magma) [1] cat [-Factorial(n-1)*Factorial(n+1): n in [1..30]]; // G. C. Greubel, Feb 08 2024
(SageMath) [1]+[-factorial(n-1)*factorial(n+1) for n in range(1, 31)] # G. C. Greubel, Feb 08 2024
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Wolfdieter Lang, May 04 2007
STATUS
approved