

A276526


Expansion of Product_{k>=1} 1/(1  x^(2*k) + x^(3*k)).


2



1, 0, 1, 1, 2, 2, 3, 4, 7, 8, 11, 15, 22, 27, 37, 51, 70, 90, 121, 162, 220, 288, 381, 512, 688, 902, 1197, 1598, 2127, 2809, 3722, 4949, 6581, 8699, 11519, 15301, 20305, 26862, 35581, 47208, 62591, 82859, 109756, 145506, 192856, 255388
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OFFSET

0,5


LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..1000


FORMULA

a(n) ~ c * p / r^n, where r = A075778 = 0.7548776662466927600495... is the real root of the equation r^3  r^2 + 1 = 0, p = Product_{n>1} 1/(1  r^(2*n) + r^(3*n)) = 1.9844809074648434... and c = 0.41149558866264576338190038... is the real root of the equation 1 + 8*c  23*c^2 + 23*c^3 = 0.


MATHEMATICA

nmax = 50; CoefficientList[Series[1/Product[1x^(2*k)+x^(3*k), {k, 1, nmax}], {x, 0, nmax}], x]


CROSSREFS

Cf. A264905, A266686, A275820, A275821, A276519.
Sequence in context: A014692 A058670 A215367 * A091605 A145468 A125554
Adjacent sequences: A276523 A276524 A276525 * A276527 A276528 A276529


KEYWORD

sign


AUTHOR

Vaclav Kotesovec, Nov 16 2016


STATUS

approved



