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A243408 Primes p such that 10*p-1, 10*p-3, 10*p-7 and 10*p-9 are all prime.

%I A243408 #28 Jun 14 2025 07:13:28
%S A243408 2,11,83,149,347,1301,1607,2531,6299,7727,8273,17117,20183,21737,
%T A243408 24371,26669,39227,40277,53951,54917,63347,66359,66467,73637,82217,
%U A243408 82373,101537,102251,106397,106871,117203,132971,134033,135221,140237,144701,146141,151433,152597
%N A243408 Primes p such that 10*p-1, 10*p-3, 10*p-7 and 10*p-9 are all prime.
%C A243408 This is a subsequence of A064975.
%H A243408 Harvey P. Dale, <a href="/A243408/b243408.txt">Table of n, a(n) for n = 1..1000</a>
%e A243408 2 is prime, 10*2-1 = 19 is prime, 10*2-3 = 17 is prime, 10*2-7 = 13 is prime, 10*2-9 = 11 is prime. Thus 2 is a member of this sequence.
%t A243408 Select[ Range@ 153000,PrimeQ[#] && PrimeQ[10#-1] && PrimeQ[10#-3] && PrimeQ[10#-7] && PrimeQ[10#-9] &] (* _Robert G. Wilson v_, Jun 06 2014 *)
%t A243408 Select[Prime[Range[15000]],AllTrue[10#-{1,3,7,9},PrimeQ]&] (* _Harvey P. Dale_, Aug 18 2024 *)
%o A243408 (Python)
%o A243408 import sympy
%o A243408 from sympy import isprime
%o A243408 from sympy import prime
%o A243408 {print(prime(n),end=', ') for n in range(1,10**5) if isprime(10*prime(n)-1) and isprime(10*prime(n)-3) and isprime(10*prime(n)-7) and isprime(10*prime(n)-9)}
%o A243408 (PARI) for(n=1,10^5,if(ispseudoprime(10*prime(n)-1) && ispseudoprime(10*prime(n)-3) && ispseudoprime(10*prime(n)-7) && ispseudoprime(10*prime(n)-9),print1(prime(n),", ")))
%Y A243408 Cf. A067267, A064975.
%K A243408 nonn
%O A243408 1,1
%A A243408 _Derek Orr_, Jun 04 2014