A171993 Numbers that are neither prime nor multiples of 3.

1, 4, 8, 10, 14, 16, 20, 22, 25, 26, 28, 32, 34, 35, 38, 40, 44, 46, 49, 50, 52, 55, 56, 58, 62, 64, 65, 68, 70, 74, 76, 77, 80, 82, 85, 86, 88, 91, 92, 94, 95, 98, 100, 104, 106, 110, 112, 115, 116, 118, 119, 121, 122, 124, 125, 128, 130, 133, 134, 136, 140, 142, 143

Offset: 1

Author

Juri-Stepan Gerasimov, Jan 21 2010

Keywords

• nonn
• less

Comments

1 together with composite numbers that are not multiples of 3.

Crossrefs

Cf. A018252, A157695.

Formula

a(n) = A157695(n-1), n>1. [From R. J. Mathar, Feb 07 2010]

a(n) ~ 1.5n.

Extensions

Edited by Charles R Greathouse IV, Mar 19 2010