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A084947
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Product(7*i+2,i=0..n-1).
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16
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1, 2, 18, 288, 6624, 198720, 7352640, 323516160, 16499324160, 956960801280, 62202452083200, 4478576549990400, 353807547449241600, 30427449080634777600, 2829752764499034316800, 282975276449903431680000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| A084947(n) = A084942(n)/A000142(n)*A000079(n) = 7^n*pochhammer(2/7, n) = 7^n*GAMMA(n+2/7)/GAMMA(2/7)
a(0) = 1; a(n) = (7*n - 5)*a(n-1) for n > 0. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 10 2008]
G.f.: 1/(1-2x/(1-7x/(1-9x/(1-14x/(1-16x/(1-21x/(1-23x/(1-28x/(1-... (continued fraction). - DELEHAM Philippe, Jan 08 2012
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MAPLE
| a := n->product(7*i+2, i=0..n-1); [seq(a(j), j=0..30)];
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MATHEMATICA
| s=1; lst={s}; Do[s+=n*s; AppendTo[lst, s], {n, 1, 5!, 7}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 08 2008]
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PROG
| (MAGMA) [ 1 ] cat [ &*[ (7*k+2): 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. A000165, A008544, A001813, A045754, A047055, A047657, A084947, A084948, A084949, A144739, A144827, A049209, A051188.
Sequence in context: A138275 A127134 A131455 * A123385 A121564 A092563
Adjacent sequences: A084944 A084945 A084946 * A084948 A084949 A084950
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KEYWORD
| easy,nonn
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AUTHOR
| Daniel Dockery (peritus(AT)gmail.com) Jun 13 2003
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EXTENSIONS
| a(15) from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 10 2008
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