A160621 Numerator of Laguerre(n, 1).

1, 0, -1, -2, -5, -7, -37, -17, 887, 1405, 168919, 958271, 3086837, 122693929, 559876951, 15779421743, 337767590383, 1531923385313, 11912361112367, -6819537030283, -21032925955607701, -313699426574980519, -16703816669710968821, -212752402370938916881

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..450

Formula

Numerators of coefficients in expansion of exp(-x/(1 - x))/(1 - x). - Ilya Gutkovskiy, Aug 29 2018

Example

1, 0, -1/2, -2/3, -5/8, -7/15, -37/144, -17/420, 887/5760, 1405/4536, 168919/403200, 958271/1995840, ... = A160621/A160622.

Mathematica

Numerator/@LaguerreL[Range[0, 30], 1]  (* Harvey P. Dale, May 01 2011 *)

Prog

(PARI) for(n=0, 30, print1(numerator(sum(k=0, n, binomial(n, k)*((-1)^k/k!))), ", ")) \\ G. C. Greubel, May 06 2018
(Magma) [Numerator((&+[Binomial(n, k)*((-1)^k/Factorial(k)): k in [0..n]])): n in [0..30]]; // G. C. Greubel, May 06 2018

Crossrefs

For denominators see A160622.

Cf. A009940.

Sequence in context: A041875 A072188 A277056 * A028432 A019409 A123232

Adjacent sequences: A160618 A160619 A160620 * A160622 A160623 A160624

Keyword

sign,frac

Author

N. J. A. Sloane, Nov 14 2009

Status

approved