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%I #12 Sep 08 2022 08:46:14
%S 7,45,67,145,411,825,1021,4039,9069,9789,12463,15137,26313,27499
%N Numbers n such that n!! - 32 is prime.
%C Corresponding primes are 73, 25373791335626257947657609343, ... .
%C a(15) > 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[0, 50000], If[#!! - 32 > 0, PrimeQ[#!! - 32]] &]
%o (Magma) DoubleFactorial:=func< n | &*[n..2 by -2] >; [ n: n in [7..450] | IsPrime(DoubleFactorial(n) -32) ]; // _Vincenzo Librandi_, Oct 01 2015
%o (PARI) for(n=1, 1e4, if (isprime(prod(k=0, (n-1)\2, n - 2*k ) - 32),print1(n", "))) \\ _Altug Alkan_, Oct 01 2015
%Y Cf. A006882, A007749, A094144, A123910, A258616.
%K hard,more,nonn
%O 1,1
%A _Robert Price_, Sep 30 2015
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