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%I #8 Apr 28 2015 17:19:15
%S 0,1,1,1,3,1,2,4,3,1,1,1,4,10,1,11,1,2,11,14,2,8,7,3,4,4,26,21,1,4,15,
%T 10,8,4,16,29,10,3,51,17,5,12,12,48,13,45,12,1,20,17,65,12,8,95,5,12,
%U 11,8,110,38,28,8,1,23,13,5,7,11,21,2,20,32,9,66,4,2,1,20,34,97,28,80
%N a(n)= smallest m such that primorial(n)/2 + 2^m is prime.
%t k = 1/2; a = {}; Do[k = k*Prime[n]; m = 0; While[ ! PrimeQ[k + 2^m], m++ ]; Print[m]; AppendTo[a, m], {n, 100}]; a
%o (PARI) a(n)=my(t=prod(i=2,n,prime(i)),m); while(!isprime(t+2^m), m++); m \\ _Charles R Greathouse IV_, Apr 28 2015
%Y Cf. A067026, A067027, A139439-A139457, A103514.
%K nonn
%O 1,5
%A _Artur Jasinski_, Apr 21 2008
%E a(1)=0 inserted and program corrected by _Ray Chandler_, Jun 16 2013