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Search: id:A111866
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| A111866 |
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Divide n! repeatedly by i! for i from floor(n/2) down through 2; a(n) = remaining quotient. |
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+0
1
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| 1, 1, 2, 6, 3, 15, 5, 35, 35, 105, 7, 77, 77, 1001, 143, 429, 2145, 36465, 12155, 230945, 46189, 323323, 29393, 676039, 676039, 16900975, 1300075, 2340135, 334305, 9694845, 215441, 6678671, 100180065, 3305942145, 64822395, 2268783825
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OFFSET
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0,3
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EXAMPLE
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a(9): 9!/(4!*4!*3!) = 105.
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MATHEMATICA
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f[n_] := Block[{k = Floor[n/2], m = n!}, While[k > 1, While[ Mod[m, k! ] == 0, m /= k! ]; k-- ]; m]; Table[ f[n], {n, 0, 35}] (* Robert G. Wilson v *)
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PROGRAM
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(PARI) a(n)=c=n!; forstep(d=floor(n/2), 2, -1, while (c%(d!)==0, c/=d!)); c
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CROSSREFS
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Cf. A055773.
Sequence in context: A094302 A094300 A055773 this_sequence A072155 A094299 A121566
Adjacent sequences: A111863 A111864 A111865 this_sequence A111867 A111868 A111869
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KEYWORD
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nonn
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AUTHOR
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Jon Perry (perry(AT)globalnet.co.uk), Nov 23 2005
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(at)rgwv.com), Nov 25 2005
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