A362012 - OEIS

%I #13 Dec 02 2023 09:13:11

%S 6,10,12,14,18,20,24,28,30,33,36,39,40,42,48,50,51,54,55,56,57,60,65,

%T 66,69,70,72,77,78,80,84,85,87,90,91,93,95,96,98,99,100,102,108,110,

%U 111,112,114,115,117,119,120,123,126,129,130,132,133,138,140,141,144,145,150,153,154,155,156,159,160

%N Numbers k such that 1 < gcd(k, 105) < k and A007947(k) does not divide 105.

%C The asymptotic density of this sequence is 19/35. - _Amiram Eldar_, Dec 02 2023

%H Michael De Vlieger, <a href="/A362012/b362012.txt">Table of n, a(n) for n = 1..10000</a>

%H Michael De Vlieger, <a href="/A362012/a362012.png">Diagram showing numbers k in this sequence</a> instead as k mod 105, in black, else white if k is coprime to 105, purple if k = 1, red if k | 105, and gold if rad(k) | 105, magnification 10X.

%F This sequence is { N \ { A108347 U A236206 } }.

%t With[{n = 105}, Select[Range[200], And[! CoprimeQ[#, n], ! Divisible[n, Times @@ FactorInteger[#][[All, 1]]]] & ] ]

%Y Cf. A007947, A108347, A236206.

%K nonn

%O 1,1

%A _Michael De Vlieger_, Apr 04 2023