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Search: id:A081512
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| A081512 |
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a(n) = smallest number which can be expressed as the sum of n of its distinct divisors. In the following triangle the n-th row contains the n divisors pertaining to the this sequence. a(n) = sum of the n-th row. |
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+0
3
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OFFSET
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1,3
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COMMENT
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1
- -
1 2 3
1 2 3 6
1 2 3 6 12
1 2 3 4 6 8
1 2 3 6 8 12 16
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EXAMPLE
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a(2) = 0. All other entries are nonzero.
24 is a sum of 6 of its divisors. Namely, 1+2+3+4+6+8=24. Furthermore, 24 is the smallest natural number with at least 6 divisors (not including itself), so it must be the smallest natural number that is a sum of 6 of its divisors.
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CROSSREFS
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Cf. A081513, A081514.
Sequence in context: A055458 A078472 A005694 this_sequence A096387 A094185 A074902
Adjacent sequences: A081509 A081510 A081511 this_sequence A081513 A081514 A081515
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KEYWORD
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nonn,more
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 27 2003
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EXTENSIONS
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Corrected by Caleb M. Shor (cshor(AT)bates.edu), Sep 26 2007
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