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A114800
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Octuple factorial, 8-factorial, n!8, n!!!!!!!!.
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5
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1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 33, 48, 65, 84, 105, 128, 153, 360, 627, 960, 1365, 1848, 2415, 3072, 3825, 9360, 16929, 26880, 39585, 55440, 74865, 98304, 126225, 318240, 592515, 967680, 1464645, 2106720, 2919735, 3932160, 5175225, 13366080
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| Eric Weisstein's World of Mathematics, Multifactorial.
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FORMULA
| a(n) = 1 for n<1, else a(n) = n*a(n-8).
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EXAMPLE
| a(10) = 10 * a(10-8) = 10 * a(2) = 10 * 2 = 20.
a(20) = 20 * a(20-8) = 20 * a(12) = 20 * (12*a(12-8)) = 20 * 12 * a(4) = 20 * 12 * 4 = 960.
a(30) = 30 * a(30-8) = 30 * a(22) = 30 * (22*a(22-8)) = 30 * 22 * a(14) = 30 * 22 * (14*a(14-8)) = 30 * 22 * 14 * 6 = 55440.
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CROSSREFS
| Cf. A000142, A006882, A007661, A007662, A085157, A085158.
Sequence in context: A122619 A098779 A180412 * A079170 A076105 A094280
Adjacent sequences: A114797 A114798 A114799 * A114801 A114802 A114803
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KEYWORD
| easy,nonn
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AUTHOR
| Jonathan Vos Post (jvospost3(AT)gmail.com), Feb 18 2006
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