A130908 E.g.f.: exp(x+x^2/2!+x^3/3!)/(1-x).

1, 2, 6, 23, 106, 576, 3622, 26006, 210828, 1910096, 19162096, 211095732, 2534829376, 32962249568, 461527198056, 6923249156336, 110774157354832, 1883174989346016, 33897247428278368, 644048388555567536, 12880972761058252896, 270500465268345299072, 5951010522336442007776, 136873244273143429751328

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Formula

a(n) ~ n! * exp(5/3). - Vaclav Kotesovec, Aug 04 2014

D-finite with recurrence +2*a(n) +2*(-n-1)*a(n-1) +(n-1)*(n-2)*a(n-3) +(n-1)*(n-2)*(n-3)*a(n-4)=0. - R. J. Mathar, Aug 20 2021

Mathematica

With[{nn=20}, CoefficientList[Series[Exp[x+x^2/2!+x^3/3!]/(1-x), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jun 01 2014 *)

Prog

(PARI) x='x+O('x^66); Vec(serlaplace(exp(x+x^2/2!+x^3/3!)/(1-x))) \\ Joerg Arndt, Jun 01 2014

Crossrefs

Cf. A130905, A130906, A130907.

Sequence in context: A336070 A187761 A277176 * A200404 A000772 A200405

Adjacent sequences: A130905 A130906 A130907 * A130909 A130910 A130911

Keyword

nonn

Author

Karol A. Penson, Jun 08 2007

Extensions

Incorrect initial term 1 removed by Harvey P. Dale, Jun 01 2014

Status

approved