login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A153176
Coefficients of the eighth-order mock theta function V_0(q).
8
1, 2, 4, 4, 6, 8, 8, 12, 16, 18, 24, 28, 32, 40, 48, 56, 66, 80, 92, 108, 128, 144, 168, 196, 224, 258, 296, 336, 384, 440, 496, 564, 640, 720, 816, 920, 1030, 1160, 1304, 1456, 1632, 1824, 2032, 2268, 2528, 2808, 3120, 3468, 3840, 4258, 4716, 5208, 5760, 6360
OFFSET
0,2
LINKS
B. Gordon and R. J. McIntosh, Some eighth order mock theta functions, J. London Math. Soc. 62 (2000), 321-335.
FORMULA
V_0(q) = -1 + 2*Sum_{n >= 0} q^(n^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*sqrt(n)). - Vaclav Kotesovec, Jun 12 2019
MATHEMATICA
nmax = 100; CoefficientList[Series[-1 + 2*Sum[x^(k^2) * Product[(1 + x^(2*j - 1))/(1 - x^(2*j - 1)), {j, 1, k}], {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 = -1 + 2* sum(n = 0, nn, q^(n^2) * prod(k = 1, n, 1 + q^(2*k-1)) / prod(k = 1, n, 1 - q^(2*k-1))); Vec(gf) \\ Michel Marcus, Jun 18 2013
CROSSREFS
Other '8th-order' mock theta functions are at A153148, A153149, A153155, A153156, A153172, A153174, A153178.
Sequence in context: A023847 A279667 A000061 * A229144 A263021 A112921
KEYWORD
nonn
AUTHOR
Jeremy Lovejoy, Dec 20 2008
EXTENSIONS
More terms from Michel Marcus, Feb 23 2015
STATUS
approved