A348847 Numbers k where the ratios A099378(k)/k reach a record value.

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

Offset: 1

Author

Amiram Eldar, Nov 02 2021

Keywords

• nonn
• more

Comments

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

Examples

			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.
		

Crossrefs

Cf. A099377, A099378, A348414.

Programs

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