A348656 Numbers with record values of the denominator of the harmonic mean of their unitary divisors.

1, 2, 4, 8, 16, 26, 32, 50, 58, 64, 98, 106, 122, 128, 178, 194, 202, 218, 226, 242, 250, 256, 346, 362, 386, 394, 458, 466, 482, 512, 698, 706, 722, 746, 778, 794, 802, 818, 842, 866, 898, 914, 922, 1018, 1024, 1402, 1418, 1466, 1514, 1522, 1538, 1546, 1594, 1618

Offset: 1

Author

Amiram Eldar, Oct 28 2021

Keywords

• nonn

Comments

The corresponding record values are 1, 3, 5, 9, 17, 21, 33, 39, 45, 65, 75, ... (see the link for more values).

Examples

			The first 8 terms of A103340 are 1, 3, 2, 5, 3, 1, 4 and 9. The record values, 1, 3, 5 and 9, occur at 1, 2, 4 and 8, the first 4 terms of this sequence.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Amiram Eldar, Table of n, a(n), A103340(a(n)) for n = 1..10000

Crossrefs

The unitary version of A348414.

Cf. A103339, A103340.

Programs

Mathematica

f[p_, e_] := 2/(1 + p^(-e)); d[n_] := Denominator[Times @@ f @@@ FactorInteger[n]]; dm = 0; s = {}; Do[dn = d[n]; If[dn > dm, dm = dn; AppendTo[s, n]], {n, 1, 1000}]; s