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%I #14 Jul 23 2017 03:16:15
%S 0,2,3,8,13,19,124,199,288,359,692,3610,5316,5372,7442,8251,14288,
%T 16883,17131
%N Numbers n such that n!*3^n + 1 is prime.
%C a(20) > 25000.
%C Corresponding primes are all verified prime (i.e., not probable prime): 2, 19, 163, 264539521, 9927882482918401, 141383412854531380076544001, ...
%t Do[f=n!*3^n+1;If[PrimeQ[f],Print[{n,f}]],{n,0,25000}]
%o (PARI) isok(n) = isprime(n!*3^n + 1); \\ _Michel Marcus_, Jul 23 2017
%Y Cf. A091415, A002982, A121859.
%K nonn,more
%O 1,2
%A _Robert Price_, Jan 19 2014
%E a(1)=0 prepended by _Robert Price_, Jul 22 2017
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