A007935 Composite numbers such that some permutation of digits is a prime.

14, 16, 20, 30, 32, 34, 35, 38, 50, 70, 74, 76, 91, 92, 95, 98, 104, 106, 110, 112, 115, 118, 119, 121, 124, 125, 128, 130, 133, 134, 136, 140, 142, 143, 145, 146, 152, 154, 160, 164, 166, 169, 170, 172, 175, 176, 182, 188, 190, 194, 196, 200, 203, 209, 214, 215, 217, 218, 230, 232, 235, 236, 238, 253, 272, 275, 278, 287, 289, 290, 292, 296, 298, 299, 300

Offset: 1

Author

R. Muller

Keywords

• nonn
• base
• easy

Comments

Conjecture: a(n) ~ 3n/2. - Charles R Greathouse IV, Sep 19 2012

Links

• F. Smarandache, Only Problems, Not Solutions!

Programs

Mathematica

With[{no=300},Select[Complement[Range[no],Prime[Range[PrimePi[no]]]],MemberQ[PrimeQ[FromDigits/@Permutations[IntegerDigits[#]]],True]&]]  (* Harvey P. Dale, Feb 06 2011 *)

Extensions

More terms from Joe DeMaio (jdemaio(AT)kennesaw.edu)