%I #64 Aug 02 2024 08:58:03

%S 4,5,7,11,12,14,18,28,30,62,135,153,275,584,630,1424,1493,4419,8492,

%T 10950

%N Numbers k such that k! + (k!/2) + 1 is prime.

%C Numbers k such that A070960(k)+1 is prime.

%C No more terms < 10000. - _Vaclav Kotesovec_, Dec 12 2022

%H <a href="/A358805/b358805.txt">Table of n, a(n) for n = 1..19</a>

%H Arsen Vardanyan, <a href="/A358805/a358805_4.txt">A list of prime numbers</a>

%o (PARI) is(k) = isprime(k!+(k!/2)+1);

%Y Cf. A070960, A358878.

%K nonn,more

%O 1,1

%A _Arsen Vardanyan_, Dec 01 2022

%E a(18)-a(19) from _Vaclav Kotesovec_, Dec 09 2022

%E a(20) from _Michael S. Branicky_, Aug 02 2024