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A082731
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a(n) is the smallest number k such that A033880(k)= n, or 0 if no such number exists, where A033880 is the abundance of k.
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2
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6, 0, 20, 18, 12, 0, 8925, 196, 56, 0, 40, 0, 24, 0, 272, 0, 550, 100, 208, 36, 176, 0, 1312, 0, 112, 0, 80, 0, 48, 0, 945, 15376, 572, 0, 928, 0, 2205, 0, 5696, 162, 736, 1352, 9555, 0, 350, 0, 490, 0, 60, 0, 416, 72, 352, 0, 90, 0, 84, 0, 160, 968, 96, 0, 24704, 0, 108, 200
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OFFSET
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0,1
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COMMENTS
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Caution: so far a(n)=0 only indicates no k < 3*10^6 exists; nonexistence is not proved. - R. J. Mathar, Jul 26 2007
For each term listed as 0 in the Data section, there is no such k < 10^14. - Jon E. Schoenfield, Jan 12 2021
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LINKS
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MAPLE
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A082731 := proc(n) local k; k := 1 ; while numtheory[sigma](k)-2*k <> n do k := k+1 ; if k = 3000000 then RETURN(0) ; fi ; od ; RETURN(k) ; end: seq(A082731(n), n=0..200) ; # R. J. Mathar, Nov 07 2016
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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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