|
|
A374081
|
|
Expansion of Product_{k>=1} (1 - x^(4*k-3)) * (1 - x^(4*k)).
|
|
2
|
|
|
1, -1, 0, 0, -1, 0, 1, 0, -1, 1, 0, 0, 0, 1, 0, -1, 0, 1, -1, 0, 1, 0, -1, 0, 0, 0, -1, 0, 2, -1, -1, 1, 0, -1, 0, 1, 0, -1, 0, 1, 0, -1, 1, 1, 0, -2, 1, 1, -2, 0, 2, 0, -1, 0, 1, 0, -1, 0, 2, -1, -2, 1, 1, -1, -1, 1, 2, -2, -1, 2, 0, -2, 0, 2, 0, -2, 0, 2, -1, -2, 1, 2, -1, -2, 1, 2
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,29
|
|
LINKS
|
|
|
MATHEMATICA
|
nmax = 85; CoefficientList[Series[Product[(1 - x^(4 k - 3)) (1 - x^(4 k)), {k, 1, nmax}], {x, 0, nmax}], x]
a[0] = 1; a[n_] := a[n] = -(1/n) Sum[DivisorSum[k, # &, Or[Mod[#, 4] == 0, Mod[#, 4] == 1] &] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 85}]
|
|
CROSSREFS
|
Cf. A010815, A035362, A042948, A081362, A082303, A106459, A137569, A274719, A284313, A301504, A374058, A374060, A374080.
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|