A348654 Indices of records in the sequence of unitary harmonic means A103339(k)/A103340(k).

1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 28, 30, 42, 60, 84, 105, 120, 140, 180, 210, 330, 390, 420, 660, 780, 840, 1092, 1155, 1260, 1540, 1820, 1980, 2310, 2730, 3570, 3990, 4290, 4620, 5460, 7140, 7980, 8580, 9240, 10920, 13860, 16380, 20020, 23940, 25740, 27720, 30030

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..170

Example

The unitary harmonic means of the first 6 positive integers are 1 < 4/3 < 3/2 < 8/5 < 5/3 < 2. The next record, A103339(10)/A103340(10) = 20/9, occurs at 10. Therefore, the first 7 terms of this sequence are 1, 2, 3, 4, 5, 6 and 10.

Mathematica

f[p_, e_] := 2/(1 + p^(-e)); uhmeam[n_] := Times @@ f @@@ FactorInteger[n]; s = {}; max = 0; Do[u1 = uhmeam[n]; If[u1 > max, max = u1; AppendTo[s, n]], {n, 1, 10^5}]; s

Crossrefs

The unitary version of A179971.

Cf. A103339, A103340.

Sequence in context: A078931 A018779 A018382 * A353385 A018266 A344826

Adjacent sequences: A348651 A348652 A348653 * A348655 A348656 A348657

Keyword

nonn

Author

Amiram Eldar, Oct 28 2021

Status

approved