A180534 Primes that become a different prime under the mapping 2 <=> 4.

23, 43, 223, 229, 233, 239, 241, 257, 263, 421, 433, 439, 443, 449, 457, 463, 521, 541, 1249, 1259, 1283, 1289, 1429, 1459, 1483, 1489, 1523, 1543, 1721, 1741, 2003, 2029, 2099, 2111, 2153, 2221, 2243, 2251, 2281, 2293, 2339, 2347, 2357, 2411, 2417, 2423

Offset: 1

Author

Zak Seidov and Robert G. Wilson v, Sep 09 2010

Keywords

• base
• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..2470
• Index to Primes, Primes that become a different prime under some mapping.

Crossrefs

Cf. A171021, A175791, A180517 thru A180559, A175789, A180560, A180561.

Programs

Mathematica

fQ[n_] := Block[{id = IntegerDigits@n}, (MemberQ[id, 2] || MemberQ[id, 4]) && PrimeQ[ FromDigits[ id /. {2 -> 4, 4 -> 2}] ]]; Select[ Prime@ Range@ 400, fQ]