A176540 1 together with the semiprimes.

1, 4, 6, 9, 10, 14, 15, 21, 22, 25, 26, 33, 34, 35, 38, 39, 46, 49, 51, 55, 57, 58, 62, 65, 69, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 106, 111, 115, 118, 119, 121, 122, 123, 129, 133, 134, 141, 142, 143, 145, 146, 155, 158, 159, 161, 166, 169, 177, 178, 183, 185, 187

Offset: 1

Author

Juri-Stepan Gerasimov, Apr 19 2010

Keywords

• nonn

Comments

The products of two noncomposite numbers that do not contain prime numbers.

Crossrefs

Cf. A001358, A037143.

Programs

Mathematica

Join[{1},Select[Range[200],PrimeOmega[#]==2&]] (* Harvey P. Dale, Dec 31 2015 *)

Extensions

Definition and comment swapped by Michel Marcus, Aug 09 2014