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A113335
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a(n) = 3^5 * binomial(n+4, 5).
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3
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243, 1458, 5103, 13608, 30618, 61236, 112266, 192456, 312741, 486486, 729729, 1061424, 1503684, 2082024, 2825604, 3767472, 4944807, 6399162, 8176707, 10328472, 12910590, 15984540, 19617390, 23882040, 28857465, 34628958, 41288373, 48934368, 57672648, 67616208
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = 3^5 * binomial(n+4, 5), n >= 1.
G.f.: 243*x/(1-x)^6.
E.g.f.: (81/40)*x*(120 + 240*x + 120*x^2 + 20*x^3 + x^4)*exp(x). (End)
Sum_{n>=1} 1/a(n) = 5/972.
Sum_{n>=1} (-1)^(n+1)/a(n) = 80*log(2)/243 - 655/2916. (End)
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MAPLE
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seq(binomial(n+4, 5)*3^5, n=1..27);
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MATHEMATICA
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With[{c=3^5}, Table[c Binomial[n+4, 5], {n, 30}]] (* Harvey P. Dale, Apr 11 2011 *)
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PROG
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(Magma) [3^5*Binomial(n+4, 5): n in [1..30]]; // G. C. Greubel, May 17 2021
(Sage) [3^5*binomial(n+4, 5) for n in (1..30)] # G. C. Greubel, May 17 2021
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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