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A094144 Numbers n such that n!! - 2 is prime. 11
5, 7, 15, 17, 19, 51, 73, 89, 131, 153, 245, 333, 441, 463, 825, 1771, 2027, 9157, 10875, 20515 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(21) > 50000. - Robert Price, Apr 14 2015

LINKS

Table of n, a(n) for n=1..20.

C. K. Caldwell, The Prime Glossary, multifactorial prime

Joe McLean, Interesting Sources of Probable Primes

MATHEMATICA

Select[Range[0, 50000], PrimeQ[#!! - 2] &] (* Robert Price, Apr 14 2014 *)

CROSSREFS

Cf. A076185.

Sequence in context: A030755 A170827 A081965 * A031069 A050851 A058918

Adjacent sequences:  A094141 A094142 A094143 * A094145 A094146 A094147

KEYWORD

nonn

AUTHOR

Lekraj Beedassy, May 04 2004

EXTENSIONS

Corrected by Robert G. Wilson v, May 05 2004

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008

STATUS

approved

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Last modified December 4 05:11 EST 2016. Contains 278748 sequences.