OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..2500
N. J. A. Sloane, Theta series and magic numbers for diamond and certain ionic crystal structures, J. Math. Phys. 28 (1987), 1653-1657.
FORMULA
MATHEMATICA
terms = 105; s = 6 q QPochhammer[q^9]^3/QPochhammer[q^3] + O[q]^(terms+5); CoefficientList[s, q][[1 ;; terms]] (* Jean-François Alcover, Jul 06 2017, after Michael Somos *)
CoefficientList[Series[6 q QPochhammer[q^9]^3/QPochhammer[q^3], {q, 0, 100}], q] (* G. C. Greubel, Aug 10 2018 *)
PROG
(PARI) my(q='q+O('q^100)); concat([0], Vec(6*q*eta(q^9)^3/eta(q^3))) \\ G. C. Greubel, Aug 10 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 05 2012
EXTENSIONS
Name edited by Andrey Zabolotskiy, Jun 21 2022
STATUS
approved