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A277370
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Positive integers k that divide 7^k + 2.
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6
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1, 3, 15, 69, 2155, 34073, 876047637, 97090036327, 420397381695, 2125899832395, 3177544777277, 34434175473881, 40845965389135
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OFFSET
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1,2
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COMMENTS
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All terms are odd.
No other terms below 10^15. Some larger terms: 21419515204636141, 5623143546839445899891, 46186634668308298262543001. - Max Alekseyev, Oct 18 2016
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LINKS
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FORMULA
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A066438(a(n)) = a(n) - 2 for n > 1.
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EXAMPLE
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7^3 + 2 = 345 = 3 * 115, so 3 is a term.
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MATHEMATICA
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Select[Range[1, 9999, 2], Divisible[7^# + 2, #] &] (* Alonso del Arte, Oct 11 2016 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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