A335650 Numbers that are multiples of 2,3,5, or 7 but not multiples of the product of any combination of 2,3,5, and 7.

2, 3, 4, 5, 7, 8, 9, 16, 22, 25, 26, 27, 32, 33, 34, 38, 39, 44, 46, 49, 51, 52, 55, 57, 58, 62, 64, 65, 68, 69, 74, 76, 77, 81, 82, 85, 86, 87, 88, 91, 92, 93, 94, 95, 99, 104, 106, 111, 115, 116, 117, 118, 119, 122, 123, 124, 125, 128, 129, 133, 134, 136, 141, 142

Offset: 1

Author

Peter Andrew, Jun 15 2020

Keywords

• nonn

Examples

			4 is a term because 4 = 2 * 2;
77 is a term because 77 = 7 * 11;
6 is not a term because 6 = 2 * 3;
21 is not a term because 21 = 3 * 7;
30 is not a term because 30 = 2 * 3 * 5;
210 is not a term because 210 = 2 * 3 * 5 * 7.
		

Crossrefs

Cf. A126590.

Programs

Haskell

a335650 = [x | x <- [0..], (gcd x 210) `elem` [2,3,5,7]]

Maple

q:= n-> is(igcd(n, 210) in {2,3,5,7}):
select(q, [$0..200])[];  # Alois P. Heinz, Jun 16 2020

Mathematica

Select[Range[150], Count[IntegerExponent[#, {2, 3, 5, 7}], 0] == 3 &] (* Amiram Eldar, Jun 16 2020 *)