A180547 Primes that become a different prime under the mapping 4 <=> 6.

41, 47, 61, 67, 347, 367, 401, 419, 431, 461, 463, 467, 491, 601, 619, 631, 641, 643, 647, 691, 947, 967, 1049, 1069, 1409, 1427, 1447, 1493, 1499, 1609, 1627, 1667, 1693, 1699, 1847, 1867, 2141, 2161, 2417, 2459, 2467, 2477, 2617, 2647, 2659, 2677, 3041

Offset: 1

Author

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

Keywords

• base
• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Index to Primes, Primes that become a different prime under some mapping.

Crossrefs

Cf. A171032, A175791, A180517 thru A180559, A175789, A180560, A180561.

Programs

Mathematica

fQ[n_] := Block[{id = IntegerDigits@n}, (MemberQ[id, 4] || MemberQ[id, 6]) && PrimeQ[ FromDigits[ id /. {4 -> 6, 6 -> 4}] ]]; Select[ Prime@ Range@ 440, fQ]
dpQ[n_]:=(DigitCount[n,10,4]>0 || DigitCount[n,10,6]>0)&&PrimeQ[ FromDigits[ IntegerDigits[n]/.{4->a,6->b}/.{a->6,b->4}]]; Select[ Prime[ Range[500]],dpQ](* Harvey P. Dale, Feb 28 2022 *)