|
Search: id:A143895
|
|
|
| A143895 |
|
Expansion of q^(1/4) * (eta(q^2)^9 / (eta(q)^5 * eta(q^4)^4))^2 in powers of q. |
|
+0
2
|
|
| 1, 10, 47, 150, 403, 1002, 2316, 5004, 10309, 20456, 39240, 73102, 132779, 235868, 410785, 702630, 1182342, 1960418, 3206675, 5179670, 8270086, 13062994, 20427293, 31644200, 48589970, 73994118, 111802523, 167685238, 249745021, 369499928
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
FORMULA
|
Expansion of (chi(q)^4 / chi(-q))^2 in powers of q where chi() is a Ramanujan theta function.
Euler transform of period 4 sequence [ 10, -8, 10, 0, ...].
G.f. is a period 1 Fourier series which satisfies f(-1/(16 t)) = (1/2) g(t) where q = exp(2 pi i t) and g() is g.f. for A143894.
G.f.: (Product_{k>0} (1 + x^k)^5 / (1 + x^(2*k))^4)^2.
|
|
EXAMPLE
|
q^-1 + 10*q^3 + 47*q^7 + 150*q^11 + 403*q^15 + 1002*q^19 + 2316*q^23 + ...
|
|
PROGRAM
|
(PARI) {a(n) = if( n<0, 0, A = x * O(x^n); polcoeff( (eta(x^2 + A)^9 / (eta(x + A)^5 * eta(x^4 + A)^4))^2, n))}
|
|
CROSSREFS
|
Sequence in context: A003765 A138041 A000832 this_sequence A034443 A121075 A121073
Adjacent sequences: A143892 A143893 A143894 this_sequence A143896 A143897 A143898
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Michael Somos, Sep 04 2008
|
|
|
Search completed in 0.002 seconds
|
