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A023293
Primes that remain prime through 3 iterations of function f(x) = 8x + 5.
3
43, 103, 199, 1039, 1303, 2311, 2857, 3673, 4513, 4663, 5743, 5953, 8431, 9721, 12391, 14143, 14533, 17599, 18457, 19507, 21211, 23719, 24169, 25621, 28663, 29023, 31963, 33409, 35311, 36979, 37423, 40867, 40939, 43891, 44371, 44983, 45841, 46747, 46807
OFFSET
1,1
COMMENTS
Primes p such that 8*p+5, 64*p+45 and 512*p+365 are also primes. - Vincenzo Librandi, Aug 04 2010
FORMULA
a(n) == 1 (mod 6). - John Cerkan, Sep 23 2016
MATHEMATICA
Select[Prime[Range[5000]], AllTrue[Rest[NestList[8#+5&, #, 3]], PrimeQ]&] (* Harvey P. Dale, Sep 19 2022 *)
PROG
(Magma) [n: n in [1..450000] | IsPrime(n) and IsPrime(8*n+5) and IsPrime(64*n+45) and IsPrime(512*n+365)]; // Vincenzo Librandi, Aug 04 2010
CROSSREFS
Subsequence of A023230, A023262, and A105133.
Sequence in context: A106888 A142795 A325077 * A115606 A194773 A154506
KEYWORD
nonn
STATUS
approved