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A121591 Expansion of (eta(q^5)/eta(q))^6 in powers of q. 0
1, 6, 27, 98, 315, 912, 2456, 6210, 14937, 34390, 76317, 163896, 342062, 695736, 1382880, 2691586, 5139906, 9644622, 17808040, 32393370, 58113312, 102914152, 180062622, 311488920, 533124225, 903324372, 1516110165, 2521780688 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

Euler transform of period 5 sequence [ 6, 6, 6, 6, 0, ...].

G.f. A(x) satisfies 0=f(A(x), A(x^2)) where f(u, v)=u^3+v^3-u*v-12*u*v*(u+v)-125*u^2*v^2.

G.f.: x*(Product_{k>0} (1-x^(5k))/(1-x^k))^6.

PROG

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

CROSSREFS

Sequence in context: A121596 A136747 A001940 * A071734 A160507 A182821

Adjacent sequences:  A121588 A121589 A121590 * A121592 A121593 A121594

KEYWORD

nonn

AUTHOR

Michael Somos, Aug 09 2006

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Last modified February 17 10:57 EST 2012. Contains 206009 sequences.