OFFSET
0,5
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..10000
B. Gordon and R. J. McIntosh, Some eighth order mock theta functions, J. London Math. Soc. 62 (2000), 321-335.
FORMULA
V_1(q) = Sum_{n >= 0} q^((n+1)^2)(1+q)(1+q^3)...(1+q^(2n-1))/((1-q)(1-q^3)...(1-q^(2n+1))).
a(n) ~ exp(Pi*sqrt(n)/2) / (2^(5/2) * sqrt(n)). - Vaclav Kotesovec, Jun 12 2019
MATHEMATICA
nmax = 100; CoefficientList[Series[Sum[x^((k+1)^2) * Product[(1 + x^(2*j - 1)), {j, 1, k}] / Product[(1 - x^(2*j - 1)), {j, 1, k+1}], {k, 0, Floor[Sqrt[nmax]]}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Jun 12 2019 *)
PROG
(PARI) lista(nn) = {my(q = qq + O(qq^nn)); gf = sum(n = 0, nn, q^((n+1)^2) * prod(k = 1, n, 1 + q^(2*k-1)) / prod(k = 0, n, 1 - q^(2*k+1))); for (i=0, nn-1, print1(polcoeff(gf, i), ", "); ); } \\ Michel Marcus, Jun 18 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeremy Lovejoy, Dec 20 2008
EXTENSIONS
More terms from Michel Marcus, Feb 23 2015
STATUS
approved