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A049209
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- Product(7*k-1,k=0..n); sept-factorial numbers.
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10
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1, 6, 78, 1560, 42120, 1432080, 58715280, 2818333440, 155008339200, 9610517030400, 663125675097600, 50397551307417600, 4182996758515660800, 376469708266409472000, 36517561701841718784000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| Index entries for sequences related to factorial numbers
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FORMULA
| a(n)= 6*A034883(n) = (7*n-1)(!^7), n >= 1, a(0) := 1.
a(n) = Prod_{k=1..n} (7*k - 1). a(0) = 1; a(n) = (7*n - 1)*a(n-1) for n > 0. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 10 2008]
G.f.: 1/(1-6x/(1-7x/(1-13x/(1-14x/(1-20x/(1-21x/(1-27x/(1-28x/(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, 5, 5!, 7}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 08 2008]
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PROG
| (MAGMA) [ -&*[ (7*k-1): k in [0..n-1] ]: n in [1..15] ]; [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 10 2008]
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CROSSREFS
| Cf. A008543.
Row sums of triangle A051186 (scaled Stirling1 triangle).
Cf. A045754, A084947, A144739, A144827, A147585, A051188
Sequence in context: A131926 A132866 A094419 * A162656 A179498 A177556
Adjacent sequences: A049206 A049207 A049208 * A049210 A049211 A049212
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KEYWORD
| easy,nonn
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)
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