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A093831 Expansion of (eta(q^2)eta(q^10)/(eta(q)eta(q^5)))^4 in powers of q. 0
1, 4, 10, 24, 51, 104, 206, 384, 697, 1228, 2112, 3568, 5898, 9592, 15358, 24256, 37850, 58340, 88980, 134344, 200972, 298112, 438538, 640256, 928041, 1336104, 1911436, 2717776, 3842110, 5401784, 7555012, 10514176, 14562432, 20077672 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

Euler transform of period 10 sequence [ 4, 0, 4, 0, 8, 0, 4, 0, 4, 0, ...].

G.f. A(x) satisfies 0=f(A(x), A(x^2)) where f(u, v)= u^2 -v*(1+8*u+16*u*v)

G.f.: x/(Product_{k>0} (1-x^(10k-5))(1-x^(2k-1)))^4.

PROG

(PARI) a(n)=if(n<1, 0, n--; polcoeff((1/prod(k=1, (n+5)\10, 1-x^(10*k-5), 1+x*O(x^n))/prod(k=1, (n+1)\2, 1-x^(2*k-1), 1+x*O(x^n)))^4, n))

(PARI) {a(n)=local(A); if(n<1, 0, n--; A=x*O(x^n); polcoeff( (eta(x^2+A)*eta(x^10+A)/eta(x+A)/eta(x^5+A))^4, n))}

CROSSREFS

Sequence in context: A001979 A128516 A022569 * A052365 A107659 A162588

Adjacent sequences:  A093828 A093829 A093830 * A093832 A093833 A093834

KEYWORD

nonn

AUTHOR

Michael Somos, Apr 17 2004, Oct 04 2004

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com) at the suggestion of Andrew Plewe, Jun 05 2007

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Last modified February 14 23:04 EST 2012. Contains 205686 sequences.