A262839 -id:A262839 - cp's OEIS frontend

A262840 {5,7}-primes (defined in Comments).

2, 3, 5, 13, 17, 23, 41, 43, 53, 71, 79, 101, 137, 157, 181, 191, 239, 281, 379, 463, 743, 839, 863, 967, 1151, 1171, 1303, 1367, 1663, 1721, 2083, 2251, 2297, 2351, 2621, 2659, 2957, 2999, 3257, 3343, 3373, 3511, 3607, 3767, 3863, 3877, 3907, 4217, 4447

Offset: 1

Clark Kimberling, Nov 09 2015

Let S = {b(1), b(2), ..., b(k)}, where k > 1 and b(i) are distinct integers > 1 for j = 1..k. Call p an S-prime if the digits of p in base b(i) spell a prime in each of the bases b(j) in S, for i = 1..k. Equivalently, p is an S-prime if p is a strong-V prime (defined at A262729) for every permutation of the vector V = (b(1), b(2), ..., b(k)).

Clark Kimberling, Table of n, a(n) for n = 1..5000

Cf. A000040, A235635, A262839, A262829.

{b1, b2} = {5, 7};
u = Select[Prime[Range[6000]], PrimeQ[FromDigits[IntegerDigits[#, b1], b2]] &];  (* A235635 *)
v = Select[Prime[Range[6000]], PrimeQ[FromDigits[IntegerDigits[#, b2], b1]] &];  (* A262839 *)
w = Intersection[u, v]; (* A262840 *)
(* Peter J. C. Moses, Sep 27 2015 *)

cp's OEIS Frontend

A262840 {5,7}-primes (defined in Comments).

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