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Search: id:A145073
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| A145073 |
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a(n) = [x^(3^n)] Q(x,n)^(n+1) where Q(x,n) = Sum_{k=0..n} (x^(3^k) + x^(2*3^k)) for n>=0. |
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+0
4
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| 1, 2, 7, 44, 325, 3110, 34258, 436304, 6246439, 99637730, 1747851787, 33469239848, 694321125511
(list; graph; listen)
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OFFSET
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0,2
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EXAMPLE
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a(n) equals the coefficient of x^(3^n) in Q(x,n)^(n+1) where
Q(x,n) = Sum_{k=0..n} (x^(3^k) + x^(2*3^k)) for n>=0.
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PROGRAM
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(PARI) {a(n)=local(Q=sum(j=0, n, x^(3^j)+x^(2*3^j)+O(x^(3^n+1)))); polcoeff(Q^(n+1), 3^n)}
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CROSSREFS
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Cf. A007178, A145074, A145075, A145076.
Sequence in context: A103084 A041507 A158107 this_sequence A111561 A000155 A077045
Adjacent sequences: A145070 A145071 A145072 this_sequence A145074 A145075 A145076
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KEYWORD
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more,nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Oct 09 2008
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EXTENSIONS
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a(10) - a(12) from Alois P. Heinz (heinz(AT)hs-heilbronn.de), Apr 28 2009
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