OFFSET
0,7
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
J. Mc Laughlin, A. V. Sills and P. Zimmer, Rogers-Ramanujan-Slater Type Identities, Electronic J. Combinatorics, DS15, 1-59, May 31, 2008. See "2.9 Mod 9 Identities".
Eric Weisstein's World of Mathematics, Bailey Mod 9 Identities
FORMULA
G.f.: Sum_{n>=0} q^(3*n^2) * Product_{k=1..3*n} (1-x^k) / (Product_{k=1..n} (1-x^(3*k)) * Product_{k=1..2*n} (1-x^(3*k))). - Seiichi Manyama, Oct 14 2019
G.f.: Product_{k>0} (1-x^(9*k-4)) * (1-x^(9*k-5)) / ( (1-x^(9*k-3)) * (1-x^(9*k-6)) ). - Seiichi Manyama, Oct 14 2019
EXAMPLE
G.f.: 1 + q^3 - q^4 - q^5 + 2*q^6 - q^7 - q^8 + 3*q^9 - 2*q^10 + ...
PROG
(PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, (1-x^(9*k-4))*(1-x^(9*k-5))/((1-x^(9*k-3))*(1-x^(9*k-6))))) \\ Seiichi Manyama, Oct 14 2019
CROSSREFS
KEYWORD
sign
AUTHOR
Eric W. Weisstein, Mar 09 2005
STATUS
approved