A362010 Numbers k such that 1 < gcd(k, 42) < k and A007947(k) does not divide 42.

10, 15, 20, 22, 26, 30, 33, 34, 35, 38, 39, 40, 44, 45, 46, 50, 51, 52, 57, 58, 60, 62, 66, 68, 69, 70, 74, 75, 76, 77, 78, 80, 82, 86, 87, 88, 90, 91, 92, 93, 94, 99, 100, 102, 104, 105, 106, 110, 111, 114, 116, 117, 118, 119, 120, 122, 123, 124, 129, 130, 132, 133, 134, 135, 136, 138, 140, 141, 142

Offset: 1

Author

Michael De Vlieger, Apr 04 2023

Keywords

• nonn

Comments

The asymptotic density of this sequence is 5/7. - Amiram Eldar, Dec 02 2023

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000
• Michael De Vlieger, Diagram showing numbers k in this sequence instead as k mod 42, labeled and in large black circles, else gray dots if coprime to 42, purple if k = 1, red if k | 42, and gold if rad(k) | 42.

Crossrefs

Cf. A007947, A108319, A206547.

Programs

Mathematica

With[{n = 42}, Select[Range[200], And[! CoprimeQ[#, n], ! Divisible[n, Times @@ FactorInteger[#][[All, 1]]]] & ] ]

Formula

This sequence is { N \ { A108319 U A206547 } }.