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Search: id:A132316
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| A132316 |
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a(n) = [x^n] Product_{i=0..n} (1 + x^(2^i) )^(2^(n-i)). |
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+0
3
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| 1, 2, 8, 88, 2812, 284832, 96344064, 112162777984, 458279216351168, 6667184111642112512, 349410072608155198029824, 66605152356815910201401874432, 46557942811582437260863430233248768
(list; graph; listen)
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OFFSET
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0,2
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EXAMPLE
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a(2) = [x^2] (1+x)^4*(1+x^2)^2*(1+x^4) = 8;
a(3) = [x^3] (1+x)^8*(1+x^2)^4*(1+x^4)^2*(1+x^8) = 88;
a(4) = [x^4] (1+x)^16*(1+x^2)^8*(1+x^4)^4*(1+x^8)^2*(1+x^16) = 2812.
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PROGRAM
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(PARI) {a(n)=polcoeff(prod(i=0, #binary(n), (1 + x^(2^i) +x*O(x^n))^(2^(n-i))), n)}
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CROSSREFS
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Cf. A132317, A132318.
Sequence in context: A134245 A141313 A009144 this_sequence A136749 A054955 A012299
Adjacent sequences: A132313 A132314 A132315 this_sequence A132317 A132318 A132319
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Aug 18 2007
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