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Numbers n such that 2^n*(n+1)!-1 is prime.
1

%I #17 Sep 08 2022 08:45:16

%S 1,2,3,5,6,7,10,12,101,117,227,884,1323,2167,3483,6274,7887

%N Numbers n such that 2^n*(n+1)!-1 is prime.

%C a(18) > 10^4.- _Robert Price_, Mar 08 2015

%t Select[Range[1000],PrimeQ[2^# (#+1)!-1]&] (* _Harvey P. Dale_, Nov 23 2014 *)

%o (Magma) [n: n in [0..500] | IsPrime(2^n*Factorial(n+1)-1)]; // _Vincenzo Librandi_, Mar 08 2015

%o (PARI) is(n)=ispseudoprime(2^n*(n+1)!-1) \\ _Charles R Greathouse IV_, Jun 13 2017

%Y Cf. A093155.

%K nonn

%O 1,2

%A _Jorge Coveiro_, Dec 24 2004

%E a(12) from _Harvey P. Dale_, Nov 23 2014

%E a(13)-a(17) from _Robert Price_, Mar 08 2015