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Search: id:A132420
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| A132420 |
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a(n) = the (2n)th positive divisor of n!. |
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+0
1
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| 24, 15, 16, 16, 20, 24, 27, 27, 30, 30, 33, 36, 40, 40, 44, 44, 48, 50, 52, 52, 55, 57, 63, 65, 68, 68, 70, 70, 75, 77, 80, 84, 87, 87, 90, 92, 95, 95, 98, 98, 100, 104, 108, 108, 111, 114, 116, 119, 121, 121, 124, 126, 129, 132, 135, 135, 138, 138, 141, 144, 147, 150
(list; graph; listen)
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OFFSET
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4,1
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EXAMPLE
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The positive divisors of 5! = 120 are 1,2,3,4,5,6,8,10,12,15,20,24,30,40,60,120. a(5) is the 10th of these, which is 15.
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MATHEMATICA
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a = {}; For[n = 4, n < 70, n++, i = 1; c = 0; While[c < 2n, If[Mod[n!, i] == 0, c++ ]; i++ ]; AppendTo[a, i - 1]]; a - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Nov 24 2007
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CROSSREFS
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Adjacent sequences: A132417 A132418 A132419 this_sequence A132421 A132422 A132423
Sequence in context: A002550 A075605 A118661 this_sequence A109475 A105191 A033826
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Nov 20 2007
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EXTENSIONS
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Corrected and extended by Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Nov 24 2007
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