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Search: id:A051580
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| A051580 |
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(2*n+6)!!/6!!, related to A000165 (even double factorials). |
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+0
2
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| 1, 8, 80, 960, 13440, 215040, 3870720, 77414400, 1703116800, 40874803200, 1062744883200, 29756856729600, 892705701888000, 28566582460416000, 971263803654144000, 34965496931549184000, 1328688883398868992000
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Row m=6 of the array A(3; m,n) := (2*n+m)!!/m!!, m >= 0, n >= 0.
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FORMULA
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a(n) = (2*n+6)!!/6!!; e.g.f.: 1/(1-2*x)^4.
a(n)=n!*2^(n-4)/3, n>=3 - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Sep 23 2006
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CROSSREFS
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Cf. A000165, A001147(n+1), A002866(n+1), A051577-A051579 (rows m=0..5).
Adjacent sequences: A051577 A051578 A051579 this_sequence A051581 A051582 A051583
Sequence in context: A136949 A102592 A053175 this_sequence A060375 A097815 A002718
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KEYWORD
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easy,nonn
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AUTHOR
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Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)
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