A101323 Numbers n such that 2^n*(n+1)!-1 is prime.

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

Offset

1,2

Comments

a(18) > 10^4.- Robert Price, Mar 08 2015

Links

Table of n, a(n) for n=1..17.

Mathematica

Select[Range[1000], PrimeQ[2^# (#+1)!-1]&] (* Harvey P. Dale, Nov 23 2014 *)

Prog

(Magma) [n: n in [0..500] | IsPrime(2^n*Factorial(n+1)-1)]; // Vincenzo Librandi, Mar 08 2015
(PARI) is(n)=ispseudoprime(2^n*(n+1)!-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A093155.

Sequence in context: A037016 A308981 A239746 * A298705 A030051 A344308

Adjacent sequences: A101320 A101321 A101322 * A101324 A101325 A101326

Keyword

nonn

Author

Jorge Coveiro, Dec 24 2004

Extensions

a(12) from Harvey P. Dale, Nov 23 2014

a(13)-a(17) from Robert Price, Mar 08 2015

Status

approved