|
%I #18 Mar 18 2024 16:52:07
%S 1,3,4,8,9,12,15,19,23,24,33,75,92,128,139,140,167,235,284,504,524,
%T 779,804,912,1104,1439,4680,4875,5843,9033,9320,13168,14305,15800,
%U 16192,24135,26728,47535,50215,52227,54612
%N Numbers k such that 7*2^k - 3 is prime.
%C a(38) > 43035. - _Jinyuan Wang_, Jan 20 2020
%t Do[ If[ PrimeQ[ 7*2^n - 3 ], Print[ n ] ], {n, 1, 5222} ]
%t Select[Range[0, 10000],PrimeQ[(7 2^# - 3)] &] (* _Vincenzo Librandi_, Sep 29 2012 *)
%o (PARI) is(n)=ispseudoprime(7*2^n-3) \\ _Charles R Greathouse IV_, Jun 12 2017
%Y Cf. A058592 (7*2^k + 3 is prime).
%K nonn,more
%O 1,2
%A _Robert G. Wilson v_, Dec 26 2000
%E a(29)-a(31) from _Vincenzo Librandi_, Sep 29 2012
%E a(32)-a(37) from _Jinyuan Wang_, Jan 20 2020
%E a(38)-a(41) from _Michael S. Branicky_, Mar 18 2024
|
