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A261631 Expansion of Product_{k>=0} 1/(1-x^(3*k+1))^3. 1
1, 3, 6, 10, 18, 30, 46, 69, 105, 154, 219, 309, 434, 597, 813, 1100, 1476, 1959, 2585, 3387, 4410, 5709, 7353, 9414, 12001, 15231, 19242, 24205, 30348, 37902, 47165, 58500, 72342, 89169, 109599, 134337, 164221, 200226, 243537, 295496, 357732, 432117, 520858 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..42.

FORMULA

a(n) ~ exp(Pi*sqrt(2*n/3)) * Gamma(1/3)^3 / (4 * Pi^2 * sqrt(6*n)).

MATHEMATICA

nmax=50; CoefficientList[Series[Product[1/(1-x^(3*k+1))^3, {k, 0, nmax}], {x, 0, nmax}], x]

CROSSREFS

Cf. A035382, A261616, A261632.

Sequence in context: A170803 A182908 A076251 * A029864 A075111 A080014

Adjacent sequences:  A261628 A261629 A261630 * A261632 A261633 A261634

KEYWORD

nonn

AUTHOR

Vaclav Kotesovec, Aug 27 2015

STATUS

approved

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Last modified June 4 08:08 EDT 2020. Contains 334824 sequences. (Running on oeis4.)