A284607 Expansion of (eta(q^3)eta(q^6)/(eta(q)eta(q^2)))^4 in powers of q.

1, 4, 18, 52, 159, 396, 1004, 2260, 5103, 10680, 22260, 44028, 86453, 163424, 306288, 557716, 1006524, 1775844, 3105740, 5333208, 9081243, 15231504, 25343808, 41636124, 67891309, 109500440, 175378446, 278234720, 438540456, 685449000, 1064868020, 1642037524

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Formula

Convolution inverse of A121667.

a(n) ~ exp(2*Pi*sqrt(2*n/3)) / (2^(3/4) * 3^(17/4) * n^(3/4)). - Vaclav Kotesovec, Mar 30 2017

Mathematica

CoefficientList[Series[(QPochhammer[q^3] QPochhammer[q^6]/(QPochhammer[q] QPochhammer[q^2]))^4, {q, 0, 100}], q] (* Indranil Ghosh, Mar 30 2017 *)

Prog

(PARI) my(q='q+O('q^66)); Vec((eta(q^3)*eta(q^6)/(eta(q)*eta(q^2)))^4) \\ Joerg Arndt, Mar 31 2017

Crossrefs

Cf. A045484, A121667.

Sequence in context: A300493 A300876 A301486 * A297945 A320544 A020644

Adjacent sequences: A284604 A284605 A284606 * A284608 A284609 A284610

Keyword

nonn

Author

Seiichi Manyama, Mar 30 2017

Status

approved