A279334 Numerators of coefficients in expansion of exp(x)/(1 - x - x^2).

1, 2, 7, 17, 221, 893, 17347, 98221, 2542969, 2645039, 599172671, 5332129721, 207061905877, 2177714624677, 98661276360571, 1197279643886453, 8855950704414791, 5962161748599967, 49662655090649112439, 69398245985290595843, 2906296303998501464573

Offset

0,2

Links

Clark Kimberling, Table of n, a(n) for n = 0..1000

Example

(1/1) + (2/1)x + (7/2)x^2 + (17/3)x^3 + (221/24)x^4 ... ; 1/1, 2/1, 7/2, 17/3, ... = A279334/A279335.

Mathematica

z = 30; t = CoefficientList[Series[E^x/(1 - x - x^2), {x, 0, z}], x];
Numerator[t]   (* A279334 *)
Denominator[t] (* A279335 *)

Prog

(PARI) my(x='x+O('x^25)); apply(numerator, Vec(exp(x)/(1 - x - x^2))) \\ Michel Marcus, Feb 06 2021

Crossrefs

Cf. A279335.

Sequence in context: A028888 A082627 A160617 * A283957 A013062 A013092

Adjacent sequences: A279331 A279332 A279333 * A279335 A279336 A279337

Keyword

nonn,easy,frac

Author

Clark Kimberling, Dec 12 2016

Extensions

Definition corrected by Georg Fischer, Feb 06 2021

Status

approved