|
|
A360001
|
|
Expansion of Product_{k>=0} (1 - x^(k^2+4)) in powers of x.
|
|
4
|
|
|
1, 0, 0, 0, -1, -1, 0, 0, -1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, -1, 1, -1, 0, 1, 0, -1, 0, 1, -2, 1, 0, -1, 1, 1, 0, 0, 1, -2, 0, -1, -2, 1, 0, 1, 2, 1, -1, 1, 0, -2, 1, -1, -2, 0, 1, 0, 0, 1, -1, 1, 1, 0, 0, -1, -1, 1, 1, -2, 2, 0, -2, 2, 1, -3, 0, 1, -3, 2, 2, -1, 1
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,30
|
|
LINKS
|
|
|
PROG
|
(PARI) my(N=100, x='x+O('x^N)); Vec(prod(k=0, sqrtint(N), 1-x^(k^2+4)))
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=-sum(j=1, i, sumdiv(j, d, issquare(d-4)*d)*v[i-j+1])/i); v;
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|