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A121596 Expansion of q^(-1/2)(eta(q^3)/eta(q))^6 in powers of q. +0
1
1, 6, 27, 92, 279, 756, 1913, 4536, 10260, 22220, 46479, 94176, 185749, 357426, 673056, 1242404, 2252772, 4017816, 7058609, 12228060, 20911230, 35330324, 59023728, 97568712, 159693831, 258941124, 416181510, 663337512, 1048935414 (list; graph; listen)
OFFSET

0,2

FORMULA

Euler transform of period 3 sequence [ 6, 6, 0, ...].

Given g.f. A(x), then B(x)=x*A(x)^2 satisfies 0=f(B(x), B(x^2)) where f(u,v)=u^3+v^3-u*v-24*u*v*(u+v)-729*u^2*v^2.

G.f.: (Product_{k>0} (1-x^(3k))/(1-x^k))^6.

PROGRAM

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

CROSSREFS

Sequence in context: A100189 A052267 A038166 this_sequence A136747 A001940 A121591

Adjacent sequences: A121593 A121594 A121595 this_sequence A121597 A121598 A121599

KEYWORD

nonn

AUTHOR

Michael Somos, Aug 09 2006

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Last modified December 19 21:04 EST 2009. Contains 171054 sequences.


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