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A028501
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18-hyperperfect numbers: n = 18*(sigma(n)-n-1) + 1.
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2
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OFFSET
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1,1
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COMMENTS
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a(6) > 4*10^12. 8992165119733, 42052982615431201 and 1978419655654505210563957 are also terms. - Donovan Johnson, Nov 20 2012
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LINKS
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Table of n, a(n) for n=1..5.
J. S. McCranie, A study of hyperperfect numbers, J. Int. Seqs. Vol. 3 (2000) #P00.1.3
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CROSSREFS
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Cf. A000396, A007593, A220290, A028499-A028500, A028502, A034916.
Sequence in context: A035862 A003907 A043613 * A183646 A145494 A206049
Adjacent sequences: A028498 A028499 A028500 * A028502 A028503 A028504
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KEYWORD
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hard,more,nonn
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AUTHOR
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Jud McCranie
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EXTENSIONS
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a(5) from Donovan Johnson, Nov 03 2011
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STATUS
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approved
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