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A139228
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First differences of perfect numbers A000396.
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12
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22, 468, 7632, 33542208, 8556318720, 128848822272, 2305842870701260800, 2658455991569831742348849607813890048, 191561942608236104636337386514471893476304705594327040
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) > 1 (Luca, 1999).
a(n) > 4 (Luca and te Riele, 2011). (End)
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EXAMPLE
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a(1) = 22 because 6 and 28 are the first two perfect numbers, and their difference is 28 - 6 = 22.
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MATHEMATICA
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Differences[Select[Range[10000], DivisorSigma[1, #] == 2# &]] (* Alonso del Arte, Mar 05 2020 *)
Differences[PerfectNumber[Range[12]]] (* Paolo Xausa, Oct 20 2023 *)
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CROSSREFS
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KEYWORD
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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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