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A262829 (3,2)-primes (defined in Comments). 8

%I #7 Oct 26 2015 22:25:00

%S 2,3,7,13,31,37,43,67,79,151,157,181,193,223,241,271,283,307,331,349,

%T 373,397,409,421,433,463,499,571,613,619,631,643,661,673,691,733,757,

%U 769,787,829,853,877,937,997,1009,1093,1123,1129,1153,1201,1213,1231

%N (3,2)-primes (defined in Comments).

%C Let V = (b(1), b(2), ..., b(k)), where k > 1 and b(i) are distinct integers > 1 for j = 1..k. Call p a V-prime if the digits of p in base b(1) spell a prime in each of the bases b(2), ..., b(k).

%H Clark Kimberling, <a href="/A262829/b262829.txt">Table of n, a(n) for n = 1..10000</a>

%t {b1, b2} = {2, 3};

%t u = Select[Prime[Range[6000]], PrimeQ[FromDigits[IntegerDigits[#, b1], b2]] &]; (* A235266 *)

%t v = Select[Prime[Range[6000]], PrimeQ[FromDigits[IntegerDigits[#, b2], b1]] &]; (* A262829 *)

%t w = Intersection[u, v]; (* A262830 *)

%t (* _Peter J. C. Moses_, Sep 27 2015 *)

%Y Cf. A000040, A235266, A262730.

%K nonn,easy,base

%O 1,1

%A _Clark Kimberling_, Oct 24 2015

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Last modified August 23 22:05 EDT 2024. Contains 375396 sequences. (Running on oeis4.)