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A084947 Product(7*i+2,i=0..n-1). +0
11
1, 2, 18, 288, 6624, 198720, 7352640, 323516160, 16499324160, 956960801280, 62202452083200, 4478576549990400, 353807547449241600, 30427449080634777600, 2829752764499034316800, 282975276449903431680000 (list; graph; listen)
OFFSET

0,2

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]

MAPLE

a := n->product(7*i+2, i=0..n-1); [seq(a(j), j=0..30)];

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]

PROGRAM

(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]

CROSSREFS

Cf. A000165, A008544, A001813, A047055, A047657, A084948, A084949.

Sequence in context: A138275 A127134 A131455 this_sequence A123385 A121564 A092563

Adjacent sequences: A084944 A084945 A084946 this_sequence A084948 A084949 A084950

KEYWORD

easy,nonn

AUTHOR

Daniel Dockery (peritus(AT)gmail.com) Jun 13 2003

EXTENSIONS

a(15) from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 10 2008

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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