A142863 Semiprimes n (A001358) for which A000001(n) is 2.

4, 6, 9, 10, 14, 21, 22, 25, 26, 34, 38, 39, 46, 49, 55, 57, 58, 62, 74, 82, 86, 93, 94, 106, 111, 118, 121, 122, 129, 134, 142, 146, 155, 158, 166, 169, 178, 183, 194, 201, 202, 203, 205, 206, 214, 218, 219, 226, 237, 253, 254, 262, 274, 278, 289, 291, 298, 301

Offset: 1

Author

N. J. A. Sloane, Oct 03 2008

Keywords

• nonn

Comments

Semiprimes p^2 or pq with pT. D. Noe, Oct 08 2008

Links

• T. D. Noe, Table of n, a(n) for n=1..1000
• John H. Conway, Heiko Dietrich and E. A. O'Brien, Counting groups: gnus, moas and other exotica.

Crossrefs

Cf. A000001, A001358.

Extensions

More terms from R. J. Mathar, Oct 04 2008