%I #26 Jul 07 2024 22:32:44
%S 0,1,3,4,5,23,32,39,61,349,718,805,1025,1194,1550,1774,3417,7583
%N Numbers k such that 10*k! + 1 is prime.
%C a(17) > 2880. - _Jinyuan Wang_, Feb 05 2020
%C a(19) > 12000. - _Michael S. Branicky_, Jul 07 2024
%e k = 4 is a term because 10*4! + 1 = 241 is prime.
%o (PARI) is(k) = ispseudoprime(10*k!+1); \\ _Jinyuan Wang_, Feb 05 2020
%Y Cf. A002981, A051915, A076679, A076680, A076681, A076682, A076683, A178488, A180626.
%K nonn,more
%O 1,3
%A _Parthasarathy Nambi_, May 07 2007
%E a(15)-a(16) from _Jinyuan Wang_, Feb 05 2020
%E a(17) from _Michael S. Branicky_, Apr 16 2023
%E a(18) from _Michael S. Branicky_, Jul 07 2024