|
%I #12 Jun 18 2015 05:59:16
%S 7,9,13,17,25,185,197,261,407,593,1535,2129,2139,2581,4133,4665,15787,
%T 25337,27449
%N Numbers n such that n!!-16 is prime.
%C Corresponding primes are 89, 929, 135119, 34459409, ... .
%C a(20) > 50000.
%H Joe McLean, <a href="http://web.archive.org/web/20091027034731/http://uk.geocities.com/nassarawa%40btinternet.com/probprim2.htm">Interesting Sources of Probable Primes</a>
%t Select[Range[4,1000],PrimeQ[#!!-16]&] (* _Robert Price_, Jun 05 2015 *)
%t Do[f=n!! - 16; If[PrimeQ[f], Print[{n, f}]], {n, 4, 600}] (* _Vincenzo Librandi_, Jun 06 2015 *) (see comment)
%Y Cf. A006882, A007749, A094144, A123910.
%K hard,more,nonn
%O 1,1
%A _Robert Price_, Jun 05 2015
|
