|
Search: id:A109039
|
|
|
| A109039 |
|
Expansion of eta(q)eta(q^3)(eta(q^4)eta(q^6))^2/eta(q^12)^2 in powers of q. |
|
+0
2
|
|
| 1, -1, -1, -1, -1, 4, -1, 6, -1, -1, 4, -12, -1, -14, 6, 4, -1, 16, -1, 18, 4, 6, -12, -24, -1, -21, -14, -1, 6, 28, 4, 30, -1, -12, 16, -24, -1, -38, 18, -14, 4, 40, 6, 42, -12, 4, -24, -48, -1, -43, -21, 16, -14, 52, -1, 48, 6, 18, 28, -60, 4, -62, 30, 6, -1, 56, -12, 66, 16, -24, -24, -72, -1, -74, -38, -21, 18, 72, -14, 78, 4
(list; graph; listen)
|
|
|
OFFSET
|
0,6
|
|
|
FORMULA
|
Euler transform of period 12 sequence [ -1, -1, -2, -3, -1, -4, -1, -3, -2, -1, -1, -4, ...].
G.f.: Product_{k>0} (1-x^k)(1-x^(3k))(1-x^(4k))^2/(1+x^(6k))^2.
|
|
PROGRAM
|
(PARI) {a(n)=local(A); if(n<0, 0, A=x*O(x^n); polcoeff( eta(x+A)*eta(x^3+A)*eta(x^4+A)^2*eta(x^6+A)^2/eta(x^12+A)^2, n))}
|
|
CROSSREFS
|
Cf. a(n)=-A109040(n), if n>0.
Adjacent sequences: A109036 A109037 A109038 this_sequence A109040 A109041 A109042
Sequence in context: A127140 A010642 A127168 this_sequence A109040 A133828 A010779
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
Michael Somos, Jun 17 2005
|
|
|
Search completed in 0.002 seconds
|
