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Search: id:A049606
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| A049606 |
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Denominator of 2^n/n!. |
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+0
16
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| 1, 1, 1, 3, 3, 15, 45, 315, 315, 2835, 14175, 155925, 467775, 6081075, 42567525, 638512875, 638512875, 10854718875, 97692469875, 1856156927625, 9280784638125, 194896477400625, 2143861251406875, 49308808782358125, 147926426347074375
(list; graph; listen)
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OFFSET
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0,4
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COMMENT
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a(n) = A000265(A000142(n)). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 09 2004
Largest odd divisor of n!. - Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jul 10 2005
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LINKS
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T. D. Noe, Table of n, a(n) for n=0..100
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FORMULA
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Product_{k=1..n} A000265(k).
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MAPLE
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f := n -> n! * 2^(add(i, i=convert(n, base, 2))-n); [From Peter Luschny (peter(AT)luschny.de), May 02 2009]
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CROSSREFS
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Numerators give A001316. Cf. A000680.
Cf. A008977, A139541.
Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), May 24 2009: (Start)
Factor of A160481.
(End)
Sequence in context: A078631 A046983 A067655 this_sequence A046126 A143257 A089403
Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Nov 23 2009: (Start)
Equals A003148 divided by A123746.
(End)
Adjacent sequences: A049603 A049604 A049605 this_sequence A049607 A049608 A049609
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KEYWORD
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nonn,frac,easy
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Feb 05 2000
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