A108614 Semiprimes with non-semiprimes digits (no digits 4,6,9 in semiprimes).

10, 15, 21, 22, 25, 33, 35, 38, 51, 55, 57, 58, 77, 82, 85, 87, 111, 115, 118, 121, 122, 123, 133, 155, 158, 177, 178, 183, 185, 187, 201, 202, 203, 205, 213, 215, 217, 218, 221, 235, 237, 253, 278, 287, 301, 302, 303, 305, 321, 323, 327, 335, 355, 358, 371

Offset

1,1

Comments

Complement of A107342 in the class of semiprimes.

This is to semiprimes A001358 as A034844 (Primes with nonprime digits) is to primes A000040. [Jonathan Vos Post, Jul 15 2010]

Links

Table of n, a(n) for n=1..55.

Formula

{j in A001358 and j not in A179463}. [Jonathan Vos Post, Jul 15 2010]

Mathematica

cnd[n_]:=Plus@@Last/@FactorInteger[n]==2&&Union[FreeQ[IntegerDigits[n], # ]&/@{4, 6, 9}]=={True}; Select[Range[600], cnd[ # ]&]

Crossrefs

Cf. A107342, A137167.

Cf. A107665, A107666, A111494, A111496, A111697, A179336. [Jonathan Vos Post, Jul 15 2010]

Sequence in context: A055986 A045161 A105156 * A336548 A115708 A068992

Adjacent sequences: A108611 A108612 A108613 * A108615 A108616 A108617

Keyword

nonn,base

Author

Zak Seidov, Jun 13 2005

Status

approved