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Primes that remain prime through 5 iterations of function f(x) = 5x + 8.
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%I #29 Sep 08 2022 08:44:47

%S 7,7621,15937,382933,462271,518803,866941,1025407,1142503,1427347,

%T 1742473,1980067,2343619,2910031,3015283,4344121,4352269,4544209,

%U 5081893,5116543,5127043,5482531,5484379,5501473,5648221,6452899,7213897,7968469

%N Primes that remain prime through 5 iterations of function f(x) = 5x + 8.

%C Primes p such that 5*p+8, 25*p+48, 125*p+248, 625*p+1248 and 3125*p+6248 are also primes. - _Vincenzo Librandi_, Aug 05 2010

%H John Cerkan, <a href="/A023344/b023344.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) == 19 (mod 42) for n > 1. - _John Cerkan_, Oct 22 2016

%t Select[Prime[Range[550000]],And@@PrimeQ[NestList[5#+8&,#,5]]&] (* _Harvey P. Dale_, Jun 04 2011 *)

%o (Magma) [n: n in [1..10000000] | IsPrime(n) and IsPrime(5*n+8) and IsPrime(25*n+48) and IsPrime(125*n+248) and IsPrime(625*n+1248) and IsPrime(3125*n+6248)] // _Vincenzo Librandi_, Aug 05 2010

%Y Subsequence of A023220, A023255, A023286, A023316, and A111225.

%K nonn

%O 1,1

%A _David W. Wilson_