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Search: id:A132218
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| A132218 |
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Expansion of psi(-q^3)/ phi(-q) in powers of q where psi(), phi() are Ramanujan theta functions. |
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1
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| 1, 2, 4, 7, 12, 20, 32, 50, 76, 113, 166, 240, 342, 482, 672, 928, 1270, 1724, 2323, 3108, 4132, 5460, 7174, 9376, 12192, 15780, 20332, 26086, 33334, 42432, 53817, 68018, 85680, 107584, 134674, 168092, 209210, 259680, 321484, 396996, 489056, 601052
(list; graph; listen)
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OFFSET
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0,2
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FORMULA
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Expansion of q^(-3/8)* eta(q^2)* eta(q^3)* eta(q^12)/( eta(q)^2* eta(q^6)) in powers of q.
Euler transform of period 12 sequence [ 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 0, ...].
G.f.: Product_{k>0} (1+x^k)* (1+x^k+x^(2*k))* (1+x^(6*k)).
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PROGRAM
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(PARI) {a(n)= local(A); if(n<0, 0, A= x*O(x^n); polcoeff( eta(x^2+A)* eta(x^3+A)* eta(x^12+A)/ eta(x+A)^2/ eta(x^6+A), n))}
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CROSSREFS
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Sequence in context: A010672 A122515 A036372 this_sequence A101230 A128129 A014968
Adjacent sequences: A132215 A132216 A132217 this_sequence A132219 A132220 A132221
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KEYWORD
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nonn
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AUTHOR
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Michael Somos, Aug 13 2007
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