A129464 Second column (m=1) of triangle A129462 (v=2 member of a certain family).

1, -2, -6, -48, -720, -17280, -604800, -29030400, -1828915200, -146313216000, -14485008384000, -1738201006080000, -248562743869440000, -41758540970065920000, -8142915489162854400000, -1824013069572479385600000, -465123332740982243328000000

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

Cf. A129462, A129465 (m=2), A129466 (m=3).

Cf. A229020.

Sequence in context: A365286 A052717 A365287 * A175430 A003053 A113296

Adjacent sequences: A129461 A129462 A129463 * A129465 A129466 A129467

Keyword

sign,easy

Author

Wolfdieter Lang, May 04 2007

Status

approved