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%I #4 Sep 08 2022 08:45:51
%S 2,5,7,29,43,1607
%N Primes p such that 8*2^(2p)-1 is also prime.
%C These are the primes in A139481. [From _R. J. Mathar_, Mar 17 2010]
%e For p=2, 8*2^4-1=127; p=5, 8*2^10-1=8191; p=7, 8*2^14-1=131071
%o (Magma) [p: p in PrimesUpTo(4500)| IsPrime(8*2^(2*p)-1)]
%K nonn
%O 1,1
%A _Vincenzo Librandi_, Mar 15 2010
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