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%I #13 Sep 08 2022 08:45:51
%S 2,5,41,353
%N Primes p such that 3*2^p+1 is also prime.
%F A000040 INTERSECT A002253. - _R. J. Mathar_, Jan 04 2011
%e For p=2, 3*2^2+1=13; p=5. 3*2^5+1=97; p=41, 3*2^41+1=6597069766657.
%p select(p->isprime(p) and isprime(3*2^p+1),[$0..5000]); # _Muniru A Asiru_, Dec 19 2018
%t Select[Prime[Range[1000]], PrimeQ[3 2^# + 1] &] (* _Vincenzo Librandi_, Dec 19 2018 *)
%o (Magma) [p: p in PrimesUpTo(4000) | IsPrime(3*2^p+1)]
%Y Cf. A000040, A002253.
%K nonn,more
%O 1,1
%A _Vincenzo Librandi_, Mar 09 2010
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