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A115155 Expansion of a newform level 15 weight 3 and nontrivial character. +0
2
1, 1, -3, -3, 5, -3, 0, -7, 9, 5, 0, 9, 0, 0, -15, 5, -14, 9, -22, -15, 0, 0, 34, 21, 25, 0, -27, 0, 0, -15, 2, 33, 0, -14, 0, -27, 0, -22, 0, -35, 0, 0, 0, 0, 45, 34, -14, -15, 49, 25, 42, 0, -86, -27, 0, 0, 66, 0, 0, 45, -118, 2, 0, 13, 0, 0, 0, 42, -102, 0, 0, -63, 0, 0, -75, 66, 0, 0, 98, 25, 81, 0, 154, 0 (list; graph; listen)
OFFSET

1,3

LINKS

S. R. Finch, Modular Forms on SL_2(Z). see page 5

W. Stein, Modular Forms Database.

FORMULA

a(n) is multiplicative with a(3^e) = (-3)^e, a(5^e) = 5^e, a(p^e) = p^e if e even else 0 if p == 7, 11, 13, 14 (mod 15), a(p^e) = a(p)a(p^(e-1)) -p^2*a(p^(e-2)) if p == 1, 2, 4, 8 (mod 15).

Expansion of (eta(q^3)eta(q^5))^3+(eta(q)eta(q^15))^3 in powers of q.

EXAMPLE

q +q^2 - 3*q^3 - 3*q^4 +5*q^5 - 3*q^6 - 7*q^8 +9*q^9 +5*q^10 +...

PROGRAM

(PARI) {a(n)=local(A); if(n<1, 0, n--; A=x*O(x^n); polcoeff( (eta(x^3+A)*eta(x^5+A))^3+x*(eta(x+A)*eta(x^15+A))^3, n))}

CROSSREFS

A106853(n)=a(2^n).

Sequence in context: A142961 A101777 A016555 this_sequence A136549 A077924 A003569

Adjacent sequences: A115152 A115153 A115154 this_sequence A115156 A115157 A115158

KEYWORD

sign,mult

AUTHOR

Michael Somos, Jan 14 2006

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Last modified December 7 23:50 EST 2009. Contains 170430 sequences.


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