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A101323 Numbers n such that 2^n*(n+1)!-1 is prime. 1
1, 2, 3, 5, 6, 7, 10, 12, 101, 117, 227, 884, 1323, 2167, 3483, 6274, 7887 (list; graph; refs; listen; history; text; internal format)
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: A090034 A037016 A239746 * A298705 A030051 A183071

Adjacent sequences:  A101320 A101321 A101322 * A101324 A101325 A101326

KEYWORD

nonn

AUTHOR

Jorge Coveiro (jorgecoveiro(AT)yahoo.com), 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

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Last modified January 16 19:49 EST 2019. Contains 319206 sequences. (Running on oeis4.)