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Search: id:A109844
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| A109844 |
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a(1) = 1, a(2) = 2, next terms up to a(2n-1) are obtained by multiplying previous terms a(n-1) by n+1, a(n-2) by n+2 etc. a(2) by (2n-2) and a(1) by 2n-1. On similar lines a(2n) = 2n*a(2n-2), a(2n+1) = (2n+1)*a(2n-1) and so on. |
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+0
1
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| 1, 2, 3, 8, 5, 48, 21, 16, 9, 160, 231, 576, 65, 112, 45, 32, 17, 576, 855, 2240, 1365, 12672, 5313, 3840, 225, 416, 567, 1344, 145, 240, 93, 64, 33, 2176, 3255, 8640, 5365, 51072, 22113, 16640, 9225, 161280, 228459, 557568, 61425, 103040, 40185, 27648
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Might be called a self-dependent or bootstrap sequences. a(n) is a multiple of n by definition. Subsidiary sequences: (i) next n-1 numbers are n times the previous n-1 terms and many more such sequences by variations in coefficients. (ii) a(n) = A(109844(n))/n.
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EXAMPLE
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a(9) = 9 a(10)= 10*a(8) = 10*16 = 160., a(11)= 11*21 = 189.
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CROSSREFS
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Sequence in context: A091136 A140651 A007955 this_sequence A128779 A112283 A136182
Adjacent sequences: A109841 A109842 A109843 this_sequence A109845 A109846 A109847
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KEYWORD
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nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jul 06 2005
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EXTENSIONS
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More terms from Joshua Zucker (joshua.zucker(AT)stanfordalumni.org), May 04 2006
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