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A080964 Euler transform of period-16 sequence [2,-3,2,1,2,-3,2,-6,2,-3,2,1,2,-3,2,-3,...]. 2
1, 2, 0, 0, 4, 4, 0, 0, 2, -2, 0, 0, -8, -4, 0, 0, -4, 0, 0, 0, 8, -8, 0, 0, -8, -2, 0, 0, -16, 4, 0, 0, 6, -8, 0, 0, 12, 4, 0, 0, 8, 8, 0, 0, -8, 4, 0, 0, -8, 2, 0, 0, 24, -4, 0, 0, 0, 8, 0, 0, -16, 4, 0, 0, 12, 8, 0, 0, 16, 0, 0, 0, 10, -8, 0, 0, -24, 0, 0, 0, -8, -6, 0, 0, 16, 8, 0, 0, -24, -8, 0, 0, -16, -8, 0, 0, 8, 0, 0 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

a(4n+2)=a(4n+3)=0.

PROG

(PARI) a(n)=local(X); if(n<0, 0, X=x+x*O(x^n); polcoeff(eta(X)^-2*eta(X^2)^5*eta(X^4)^-4*eta(X^8)^7*eta(X^16)^-3, n))

CROSSREFS

a(n)=2*A072071(n)-A072070(n). a(4n)=A080965(n). a(4n+1)=2*A080966(n).

Sequence in context: A147592 A108885 A072740 * A004531 A134014 A072071

Adjacent sequences:  A080961 A080962 A080963 * A080965 A080966 A080967

KEYWORD

sign

AUTHOR

Michael Somos, Feb 28 2003

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Last modified February 17 16:49 EST 2012. Contains 206058 sequences.