|
|
A348630
|
|
Nonexponential superabundant numbers: numbers m such that nesigma(m)/m > nesigma(k)/k for all k < m, where nesigma(m) is the sum of nonexponential divisors of m (A160135).
|
|
0
|
|
|
1, 24, 30, 96, 120, 480, 840, 3360, 13440, 30240, 36960, 120960, 147840, 272160, 332640, 1330560, 2993760, 4324320, 17297280, 38918880, 73513440, 220540320, 294053760, 661620960, 1396755360, 2646483840, 5587021440, 12570798240
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
The least term k with nesigma(k)/k > m for m = 2, 3, 4, ... is 480, 332640, 1396755360, ...
|
|
LINKS
|
|
|
MATHEMATICA
|
esigma[n_] := Times @@ (Sum[First[#]^d, {d, Divisors[Last[#]]}] &) /@ FactorInteger[n]; s[1] = 1 ; s[n_] := DivisorSigma[1, n] - esigma[n]; seq = {}; rm = -1; Do[r1 = s[n]/n; If[r1 > rm, rm = r1; AppendTo[seq, n]], {n, 1, 10^6}]; seq
|
|
CROSSREFS
|
The nonexponential version of A004394.
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|