|
%I #13 May 19 2023 20:14:09
%S 1,2,3,4,5,6,12,17,43,46,50,88,110,187,472,832,834,1034,1311,1700,
%T 2756,5470,6124,7404,7891,12010,16411
%N Numbers k such that 609 * 10^k - 1 is prime.
%e a(4) = 4 because 609*10^4-1 = 6089999, a prime.
%o (PARI) is(n)=ispseudoprime(609*10^n-1) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A053580.
%K more,nonn
%O 1,2
%A _Jason Earls_, Jun 30 2005
%E a(27) from _Michael S. Branicky_, May 19 2023
|
