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Search: id:A081357
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| A081357 |
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Sublime numbers, numbers for which the number of divisors and the sum of the divisors are both perfect. |
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+0
2
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| 12, 6086555670238378989670371734243169622657830773351885970528324860512791691264
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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a(2) was calculated by K. S. Brown
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REFERENCES
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J.-M. De Koninck, Those Fascinating Numbers, Amer. Math. Soc., 2009. (From N. J. A. Sloane, Aug 28 2009)
M. J. Halm, More Sequences, Mpossibilities 83, April 2003
C. A. Pickover, Wonders of Numbers, p. 215
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LINKS
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K. S. Brown, Odd Sublime Numbers (posting to sci.math newsgroup)
K. S. Brown, Sublime Numbers
Dean Hickerson, Re: Twelve is special (posting to sci.math newsgroup)
C. A. Pickover, "Wonders of Numbers, Adventures in Mathematics, Mind and Meaning," Zentralblatt review
G. Villemin's Almanac of Numbers, Nombres Sublimes
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EXAMPLE
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a(1) = 12 because 12 + 6 + 4 + 3 + 2 + 1 = 28 is perfect and number of divisors, 6, is also perfect
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CROSSREFS
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Sequence in context: A145745 A144546 A165970 this_sequence A127708 A094896 A067155
Adjacent sequences: A081354 A081355 A081356 this_sequence A081358 A081359 A081360
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KEYWORD
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hard,nonn,bref,more
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AUTHOR
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Michael Joseph Halm (hierogamous(AT)lycos.com), Apr 20 2003
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