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Primes that remain prime through 4 iterations of function f(x) = 2x + 3.
5

%I #22 Sep 08 2022 08:44:47

%S 47,67,97,137,307,1427,2857,6047,6997,9377,12097,16057,24197,32117,

%T 35117,36877,44507,46687,54517,55487,64877,71327,71807,76537,89017,

%U 92387,94427,100057,132707,142057,153077,160207,184777,186647,194027,200117,205237

%N Primes that remain prime through 4 iterations of function f(x) = 2x + 3.

%C Primes p such that 2*p+3, 4*p+9, 8*p+21 and 16*p+45 are also primes. - _Vincenzo Librandi_, Aug 04 2010

%H Harvey P. Dale, <a href="/A023303/b023303.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Prime[Range[20000]],And@@PrimeQ[NestList[2#+3&,#,4]]&] (* _Harvey P. Dale_, Aug 12 2012 *)

%o (Magma) [ p: p in PrimesUpTo(300000) | IsPrime(p) and IsPrime(2*p+3) and IsPrime(4*p+9) and IsPrime(8*p+21) and IsPrime(16*p+45)] // _Vincenzo Librandi_, Aug 04 2010

%Y Subsequence of A023204.

%K nonn

%O 1,1

%A _David W. Wilson_