|
%I #16 Mar 18 2024 16:07:36
%S 1,2,5,6,8,9,17,76,154,188,329,497,609,1401,2320,3250,3281,5489,6868,
%T 7602,28666,30969
%N Numbers k such that 2*5^k - 3 is prime.
%t Do[ If[ PrimeQ[ 2*5^n - 3 ], Print[ n ] ], {n, 1, 2000} ]
%o (PARI) is(n)=ispseudoprime(2*5^n-3) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A057914 (2*5^k + 3 is prime).
%K nonn,more
%O 1,2
%A _Robert G. Wilson v_, Nov 16 2000
%E a(18)-a(20) from _Jinyuan Wang_, Dec 14 2019
%E a(21)-a(22) from _Michael S. Branicky_, Mar 18 2024
|
