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A047056
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Quintuple factorial numbers: product[ k=0..n-1 ] (5*k+3).
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12
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1, 3, 24, 312, 5616, 129168, 3616704, 119351232, 4535346816, 195019913088, 9360955828224, 496130658895872, 28775578215960576, 1812861427605516288, 123274577077175107584, 8999044126633782853632
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| E.g.f. (1-5*x)^(-3/5)
a(n) ~ 2^(1/2)*pi^(1/2)*Gamma(3/5)^-1*n^(1/10)*5^n*e^-n*n^n*{1 - 11/300*n^-1 + ...}. - Joe Keane (jgk(AT)jgk.org), Nov 24 2001
G.f.: 1/(1-3x/(1-5x/(1-8x/(1-10x/(1-13x/(1-15x/(1-18x/(1-20x/(1-... (continued fraction). - DELEHAM Philippe, Jan 08 2012
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MATHEMATICA
| s=1; lst={s}; Do[s+=n*s; AppendTo[lst, s], {n, 2, 5!, 5}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 08 2008]
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CROSSREFS
| Cf. A047055, A008546, A008548, A052562.
Sequence in context: A138209 A075142 A138428 * A003236 A082166 A144003
Adjacent sequences: A047053 A047054 A047055 * A047057 A047058 A047059
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KEYWORD
| nonn,easy
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AUTHOR
| Joe Keane (jgk(AT)jgk.org)
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