A326858 E.g.f.: Product_{k>=1} (1 + x^(3*k-2) / (3*k-2)).

1, 1, 0, 0, 6, 30, 0, 720, 5760, 0, 362880, 5417280, 17107200, 479001600, 8885479680, 32691859200, 1307674368000, 34151856076800, 214585052774400, 6402373705728000, 192796754895360000, 1542202547010048000, 55105230485200896000, 1944933030182596608000

Offset

0,5

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..440

Formula

a(n) ~ n! / (3^(1/3) * Gamma(2/3) * exp(gamma/3) * n^(2/3)), where gamma is the Euler-Mascheroni constant A001620 and Gamma() is the Gamma function.

Mathematica

nmax = 30; CoefficientList[Series[Product[(1+x^(3*k-2)/(3*k-2)), {k, 1, Floor[nmax/3]+1}], {x, 0, nmax}], x] * Range[0, nmax]!

Crossrefs

Cf. A007838, A088994, A326756, A326857.

Sequence in context: A122802 A144746 A051685 * A165734 A367665 A309253

Adjacent sequences: A326855 A326856 A326857 * A326859 A326860 A326861

Keyword

nonn

Author

Vaclav Kotesovec, Jul 27 2019

Status

approved