login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A123649 Expansion of eta(q)eta(q^12)^3/(eta(q^4)eta(q^3)^3) in powers of q. 1
1, -1, -1, 3, -2, -3, 8, -5, -7, 18, -12, -15, 38, -24, -30, 75, -46, -57, 140, -86, -104, 252, -152, -183, 439, -262, -313, 744, -442, -522, 1232, -725, -852, 1998, -1168, -1365, 3182, -1852, -2150, 4986, -2886, -3336, 7700, -4436, -5106, 11736, -6736, -7719, 17673, -10103, -11538, 26322 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

FORMULA

Euler transform of period 12 sequence [ -1, -1, 2, 0, -1, 2, -1, 0, 2, -1, -1, 0, ...].

G.f. A(x) satisfies 0=f(A(x), A(x^2)) where f(u, v)= u^2 -v*(1-2*(u+v)+4*u*v).

PROG

(PARI) {a(n)=local(A); if(n<1, 0, n--; A=x*O(x^n); polcoeff( eta(x+A)*eta(x^12+A)^3/eta(x^3+A)^3/eta(x^4+A), n))}

CROSSREFS

Sequence in context: A073341 A070982 A187153 * A080848 A016602 A131134

Adjacent sequences:  A123646 A123647 A123648 * A123650 A123651 A123652

KEYWORD

sign

AUTHOR

Michael Somos, Oct 04 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 19:15 EST 2012. Contains 205852 sequences.