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Primes of the form 2^n - 69.
2

%I #10 Sep 08 2022 08:45:28

%S 59,443,1979,4027,8123,524219,1048507,2097083,8388539,2147483579,

%T 34359738299,137438953403,35184372088763,144115188075855803,

%U 9444732965739290427323,19342813113834066795298747

%N Primes of the form 2^n - 69.

%C Corresponding n's are 7, 9, 11, 12, 13, 19, 20, 21, 23, 31, 35, 37, 45, 57, 73, 84, 89.

%H Vincenzo Librandi, <a href="/A125034/b125034.txt">Table of n, a(n) for n = 1..33</a>

%e 2^7-69=59 (prime), 2^9-69=443 (prime), 2^11-69=1979(prime).

%t Select[Table[2^n - 69, {n, 7, 100}], PrimeQ] (* _Vincenzo Librandi_, Mar 21 2013 *)

%o (Magma) [a: n in [7..100] | IsPrime(a) where a is 2^n - 69]; // _Vincenzo Librandi_, Mar 21 2013

%Y Cf. A124977.

%K nonn

%O 1,1

%A _Zak Seidov_, Nov 17 2006