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A028500
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12-hyperperfect numbers: n = 12*(sigma(n) - n - 1) + 1.
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5
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OFFSET
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1,1
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COMMENTS
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7056410014866537089009269921 is also a term. - Donovan Johnson, Nov 20 2012
Also terms: 13^7*815787979*11621986347871 and 13^23*542800770374370512771595349. - Giovanni Resta, Nov 18 2019
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LINKS
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PROG
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(PARI) isok(n) = 12*(sigma(n) - n - 1) + 1 == n; \\ Michel Marcus, Nov 18 2019
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CROSSREFS
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KEYWORD
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hard,more,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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