%I #13 Dec 13 2018 16:32:46
%S 2,6,8,20,54,68,468,648,1100,1374,14072,17790,20038,27192,42692
%N Numbers n such that n * 2^(n/2) - 1 is prime.
%D Posting to NMBRTHRY(AT)LISTSERV.NODAK.EDU by _Mike Oakes_ Dec 30 2000 entitled "Gaussian analogues of the Cullen and Woodall primes."
%H <a href="/index/Ga#gaussians">Index entries for Gaussian integers and primes</a>
%t Do[ If[ PrimeQ[n*2^(n/2) - 1], Print[n] ], {n, 1, 100000} ]
%t Select[Range[2,43000,2],PrimeQ[#*2^(#/2)-1]&] (* _Harvey P. Dale_, Dec 13 2018 *)
%o (PARI) is(n)=isprime(n*2^(n/2)-1) \\ _Charles R Greathouse IV_, Jun 13 2017
%K nonn,easy
%O 1,1
%A _Robert G. Wilson v_, Jan 02 2001