A139453 - OEIS

%I #7 May 22 2017 20:00:49

%S 4,5,6,7,9,12,73,129,142,144,253,455,531,734,1009,1193,1553,2449,3309,

%T 13534,17513,17832,22852

%N Numbers n such that primorial(n)/2 + 512 is prime.

%C a(24) > 25000. - _Robert Price_, May 22 2017

%t k = 1/2; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k + 512], Print[n]; AppendTo[a, n]], {n, 325}]; a

%Y Cf. A067026, A067027, A139439-A139457, A103514.

%K nonn

%O 1,1

%A _Artur Jasinski_, Apr 21 2008

%E a(12)-a(18) from _Ray Chandler_, Jun 16 2013

%E a(19)-a(23) from _Robert Price_, May 22 2017