A179463 Semiprimes A001358 containing at least one semiprime digit in base 10.

4, 6, 9, 14, 26, 34, 39, 46, 49, 62, 65, 69, 74, 86, 91, 93, 94, 95, 106, 119, 129, 134, 141, 142, 143, 145, 146, 159, 161, 166, 169, 194, 206, 209, 214, 219, 226, 247, 249, 254, 259, 262, 265, 267, 274, 289, 291, 295, 298, 299, 309, 314, 319, 326, 329, 334, 339, 341

Offset: 1

Author

Jonathan Vos Post, Jul 15 2010

Keywords

• base
• easy
• nonn
• less

Comments

Semiprimes containing at least one 4, 6, or 9 digit base 10.

This is to semiprimes A001358 as A179336 is to primes A000040.

This properly includes the subset A107342 Semiprimes with semiprime digits.

Crossrefs

Cf. A107342 Semiprimes with semiprime digits (digits 4, 6, 9 only), A107665 Numbers with semiprime digits (digits 4, 6, 9 only), A107666 Primes with semiprime digits (digits 4, 6, 9 only), A111494, A111496, A111697, A108614 Semiprimes with non-semiprimes digits (no digits 4, 6, 9 in semiprimes), A179336.

Programs

Mathematica

spdQ[n_]:=Module[{idn=IntegerDigits[n]},MemberQ[idn,4] || MemberQ[ idn,6] || MemberQ[ idn,9]]; Select[Select[Range[350],PrimeOmega[#]==2&],spdQ] (* Harvey P. Dale, Jun 24 2013 *)

Extensions

Corrected (a(37) added) by Harvey P. Dale, Jun 24 2013