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Search: id:A134322
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| A134322 |
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Positive integers with fewer non-isolated divisors than isolated divisors. A divisor, k, of n is non-isolated if (k-1) and/or (k+1) also divides n. A divisor, k, of n is isolated if neither (k-1) nor (k+1) divides n. |
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+0
3
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| 1, 3, 5, 7, 9, 11, 13, 15, 16, 17, 19, 21, 23, 25, 27, 28, 29, 31, 32, 33, 35, 36, 37, 39, 41, 43, 44, 45, 47, 48, 49, 50
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OFFSET
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1,2
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COMMENT
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All odd positive integers are in the sequence, since every divisor of any odd number is isolated.
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EXAMPLE
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The divisors of 50 are 1,2,5,10,25,50. Of these, 1 and 2 are non-isolated divisors, and 5,10,25,50 are isolated divisors. There are fewer non-isolated divisors (2 in number) than isolated divisors (4 in number), so 50 is in the sequence.
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CROSSREFS
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Cf. A134320, A134321.
Adjacent sequences: A134319 A134320 A134321 this_sequence A134323 A134324 A134325
Sequence in context: A064996 A091569 A120890 this_sequence A063460 A024806 A084834
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KEYWORD
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more,nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Oct 20 2007
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