A094144 Numbers n such that n!! - 2 is prime.

5, 7, 15, 17, 19, 51, 73, 89, 131, 153, 245, 333, 441, 463, 825, 1771, 2027, 9157, 10875, 20515

Offset: 1

Author

Lekraj Beedassy, May 04 2004

Keywords

• nonn

Comments

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

Links

• C. K. Caldwell, The Prime Glossary, multifactorial prime
• C. Caldwell and H. Dubner (Eds): The top ten prime numbers: from the unpublished collections of R. Ondrejka (May 2001), Table 21 F, p. 75
• Ken Davis, Status of Search for Multifactorial Primes.
• Joe McLean, Interesting Sources of Probable Primes

Crossrefs

Cf. A076185.

Programs

Mathematica

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

Extensions

Corrected by Robert G. Wilson v, May 05 2004

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