

A348847


Numbers k where the ratios A099378(k)/k reach a record value.


0



1, 2, 4, 8, 16, 36, 144, 576, 900, 3600, 14400, 32400, 129600, 435600, 6969600, 8643600, 34574400, 77792400, 311169600, 2498000400, 2800526400, 7779240000, 9992001600, 22482003600
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OFFSET

1,2


COMMENTS

Are there nonsquare terms in this sequence that are larger than 8?


LINKS



EXAMPLE

The first 4 ratios A099378(k)/k, for k = 1 to 4, are 1, 3/2, 2/3 and 7/4. The record values occur at k = 1, 2 and 4, the first 3 terms of this sequence.


MATHEMATICA

r[n_] := Denominator[DivisorSigma[0, n]/DivisorSigma[1, n]]/n; s = {}; rm = 0; Do[If[(r1 = r[n]) > rm, rm = r1; AppendTo[s, n]], {n, 1, 5*10^5}]; s


CROSSREFS



KEYWORD

nonn,more


AUTHOR



STATUS

approved



