A130906 Expansion of e.g.f. exp(x^3/3!)/(1-x).

1, 1, 2, 7, 28, 140, 850, 5950, 47600, 428680, 4286800, 47154800, 565873000, 7356349000, 102988886000, 1544834691400, 24717355062400, 420195036060800, 7563510839684800, 143706705954011200, 2874134119080224000, 60356816536896880000, 1327849963811731360000

Offset

0,3

Links

Table of n, a(n) for n=0..22.

Formula

a(n) ~ n! * exp(1/6). - Vaclav Kotesovec, Aug 04 2014

a(n) = n! * Sum_{k=0..floor(n/3)} 1/(6^k * k!). - Seiichi Manyama, Feb 27 2024

Mathematica

With[{nn=20}, CoefficientList[Series[Exp[x^3/6]/(1-x), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, May 10 2018 *)

Crossrefs

Cf. A000522, A130905.

Sequence in context: A276080 A352659 A030875 * A009628 A186763 A182249

Adjacent sequences: A130903 A130904 A130905 * A130907 A130908 A130909

Keyword

nonn

Author

Karol A. Penson, Jun 08 2007

Extensions

More terms from Harvey P. Dale, May 10 2018

Status

approved