|
|
A276526
|
|
Expansion of Product_{k>=1} 1/(1 - x^(2*k) + x^(3*k)).
|
|
2
|
|
|
1, 0, 1, -1, 2, -2, 3, -4, 7, -8, 11, -15, 22, -27, 37, -51, 70, -90, 121, -162, 220, -288, 381, -512, 688, -902, 1197, -1598, 2127, -2809, 3722, -4949, 6581, -8699, 11519, -15301, 20305, -26862, 35581, -47208, 62591, -82859, 109756, -145506, 192856, -255388
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,5
|
|
LINKS
|
|
|
FORMULA
|
a(n) ~ c * p / r^n, where r = -A075778 = -0.7548776662466927600495... is the real root of the equation r^3 - r^2 + 1 = 0, p = Product_{n>1} 1/(1 - r^(2*n) + r^(3*n)) = 1.9844809074648434... and c = 0.41149558866264576338190038... is the real root of the equation -1 + 8*c - 23*c^2 + 23*c^3 = 0.
|
|
MATHEMATICA
|
nmax = 50; CoefficientList[Series[1/Product[1-x^(2*k)+x^(3*k), {k, 1, nmax}], {x, 0, nmax}], x]
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|