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

1,1

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.

Formula

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

Mathematica

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

Crossrefs

Cf. A007947, A108319, A206547.

Sequence in context: A181529 A232501 A138593 * A004259 A210652 A284804

Adjacent sequences: A362007 A362008 A362009 * A362011 A362012 A362013

Keyword

nonn

Author

Michael De Vlieger, Apr 04 2023

Status

approved