A180548 Primes that become a different prime under the mapping 4 <=> 7.

41, 43, 71, 73, 149, 179, 241, 271, 349, 379, 401, 409, 419, 433, 439, 443, 461, 541, 571, 643, 673, 701, 709, 719, 733, 739, 761, 773, 941, 971, 1249, 1279, 1409, 1423, 1433, 1453, 1459, 1471, 1483, 1489, 1549, 1579, 1709, 1723, 1733, 1741, 1753, 1759

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..2779
• Index to Primes, Primes that become a different prime under some mapping.

Crossrefs

Cf. A171038, A175791, A180517 thru A180559, A175789, A180560, A180561.

Programs

Mathematica

fQ[n_] := Block[{id = IntegerDigits@n}, (MemberQ[id, 4] || MemberQ[id, 7]) && PrimeQ[ FromDigits[ id /. {4 -> 7, 7 -> 4}] ]]; Select[ Prime@ Range@ 300, fQ]