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A122779 Expansion of F(q)F(q^5) where F(q)=eta(q^2)eta(q^3)^3/(eta(q)eta(q^6)). 1
1, 1, 1, -1, -1, 1, 0, 1, -3, -1, 0, -1, 2, -4, -1, -1, -2, 1, -4, 1, 0, 0, 4, 1, 1, 2, 5, 4, 2, -1, 0, 1, 0, 6, 0, -1, 2, -4, 2, -1, 2, -4, -8, 0, 3, 0, -4, -1, 1, 1, -2, -2, -6, 1, 0, -4, -4, -6, 8, 1, -2, 8, -8, -1, -2, 0, 0, -6, 4, 4, -8, 1, 2, 2, 1, 4, 0, 2, 8, 1, 1, -6, 8, 4, 2, -4, 2, 0, 2, -1, 0, 0, 0, 0, 4, 1, 2, 9, 0, -1, 10, 6, 8, 2, 0 (list; graph; refs; listen; history; internal format)
OFFSET

1,9

FORMULA

Euler transform of period 30 sequence [ 1, 0, -2, 0, 2, -2, 1, 0, -2, 0, 1, -2, 1, 0, -4, 0, 1, -2, 1, 0, -2, 0, 1, -2, 2, 0, -2, 0, 1, -4, ...].

PROG

(PARI) {a(n)=local(A); if(n<1, 0, n--; A=x*O(x^n); A=eta(x^2+A)*eta(x^3+A)^3/eta(x+A)/eta(x^6+A); A=A*subst(A+x*O(x^(n\5)), x, x^5); polcoeff(A, n))}

CROSSREFS

A122777(n)=a(2n).

Sequence in context: A183134 A053382 A031253 * A120323 A099905 A085391

Adjacent sequences:  A122776 A122777 A122778 * A122780 A122781 A122782

KEYWORD

sign

AUTHOR

Michael Somos, Sep 10 2006

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Last modified February 15 03:59 EST 2012. Contains 205694 sequences.