|
|
A053268
|
|
Coefficients of the '6th-order' mock theta function phi(q).
|
|
12
|
|
|
1, -1, 2, -1, 1, -3, 3, -3, 4, -4, 6, -6, 5, -9, 11, -10, 11, -15, 17, -16, 19, -22, 26, -29, 29, -36, 42, -42, 46, -55, 60, -64, 71, -79, 90, -95, 101, -117, 131, -137, 148, -169, 184, -195, 211, -234, 258, -276, 295, -327, 360, -379, 409, -453, 489, -522, 563, -612, 666, -710, 757, -829, 898
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
REFERENCES
|
Srinivasa Ramanujan, The Lost Notebook and Other Unpublished Papers, Narosa Publishing House, New Delhi, 1988, pp. 2, 4, 6, 13, 16, 17
|
|
LINKS
|
|
|
FORMULA
|
G.f.: phi(q) = sum for n >= 0 of (-1)^n q^n^2 (1-q)(1-q^3)...(1-q^(2n-1))/((1+q)(1+q^2)...(1+q^(2n))).
a(n) ~ (-1)^n * exp(Pi*sqrt(n/6)) / (2*sqrt(3*n)). - Vaclav Kotesovec, Jun 15 2019
|
|
MATHEMATICA
|
Series[Sum[(-1)^n q^n^2 Product[1-q^k, {k, 1, 2n-1, 2}]/Product[1+q^k, {k, 1, 2n}], {n, 0, 10}], {q, 0, 100}]
nmax = 100; CoefficientList[Series[Sum[(-1)^k * x^(k^2) * Product[1-x^j, {j, 1, 2*k-1, 2}] / Product[1+x^j, {j, 1, 2*k}], {k, 0, Floor[Sqrt[nmax]]}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Jun 15 2019 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|