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Numbers n such that n!!! + 1 is prime (0 is included by convention).
18

%I #25 Mar 03 2017 11:56:04

%S 0,1,2,4,5,6,7,9,10,11,17,24,29,39,40,57,58,59,91,155,175,245,359,372,

%T 597,864,977,1077,1327,2076,4798,4975,10830,13453,15472,15948,16116,

%U 16681,18037,21725,22326,24753,28565,32659,46487,50649,51393,80069,95493

%N Numbers n such that n!!! + 1 is prime (0 is included by convention).

%C n!!! = n(n-3)(n-6)(n-9)...

%C The search for multifactorial primes started by Ray Ballinger is now continued by a team of volunteers on the website of Ken Davis (see link).

%H Ray Ballinger, <a href="http://web.archive.org/web/20160604135248/http://www.prothsearch.net/multifac.html">Status of Search for Multifactorial Primes</a>

%H Ken Davis, <a href="http://mfprimes.free-dc.org">Status of Search for Multifactorial Primes.</a>

%H Ken Davis, <a href="http://mfprimes.free-dc.org/mfdata/f03p.html">Results for n!3+1.</a>

%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>

%Y Cf. A007661 (triple factorials), A084438, A037082.

%K nonn

%O 1,3

%A _G. L. Honaker, Jr._

%E More terms from _Steven Harvey_

%E Corrected and extended by _Hugo Pfoertner_, Jun 25 2003

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

%E Edited by _N. J. A. Sloane_, Jan 14 2008