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Primes of the form 2^(2^n) + 805.
1

%I #8 Sep 08 2022 08:46:17

%S 809,821,1061,4294968101,18446744073709552421

%N Primes of the form 2^(2^n) + 805.

%C Terms given correspond to n = 1, 2, 3, 5 and 6.

%C Next term >= 2^2^25 + 805. - _Charles R Greathouse IV_, Jun 07 2016

%t Select[Table[2^(2^n) + 805, {n, 0, 15}], PrimeQ]

%o (Magma) [a: n in [0..16] | IsPrime(a) where a is 2^(2^n)+805];

%o (PARI) for(n=1,6, if(ispseudoprime(t=2^2^n+805), print1(t", "))) \\ _Charles R Greathouse IV_, Jun 07 2016

%Y Cf. similar sequences listed in A273547.

%K nonn

%O 1,1

%A _Vincenzo Librandi_, Jun 03 2016