%I

%S 1,15,22,27,28,36,43,45,48,50,52,58,60,63,64,67,70,77,80,82,83,84,85,

%T 86,97

%N n!-x!+1 is never prime for x<n.

%o (PARI) for (a=1,100,c=0; for (b=1,a-1, if (b%2<>a%2,continue); if (isprime(a!-b!+1),c=1; break)); if (c==0,print1(a,",")))

%Y Cf. A076378.

%K nonn

%O 1,2

%A _Jon Perry_, Oct 08 2002