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%I #35 Apr 03 2023 10:36:13
%S 7,9,11,15,17,19,39,45,57,59,63,69,81,85,127,141,149,153,163,165,201,
%T 235,259,377,457,649,815,897,1057,1433,1453,1519,1759,3047,3561,4151,
%U 7025,11917,11971,15295,18919,19449,20765,70385,71293
%N Numbers k such that k![4] - 4 is prime, where k![4] = A007662(k) = quadruple factorial.
%C a(46) > 10^5.
%C The first 6 primes associated with this sequence are: 17, 41, 227, 3461, 9941, 65831.
%H C. K. Caldwell, The Prime Glossary, <a href="https://t5k.org/glossary/page.php/MultifactorialPrime.html">multifactorial prime</a>
%H C. Caldwell and H. Dubner (Eds): <a href="https://t5k.org/lists/top_ten/">The top ten prime numbers: from the unpublished collections of R. Ondrejka</a> (May 2001), Table 21 F, p. 75
%H Ken Davis, <a href="http://mfprimes.free-dc.org">Status of Search for Multifactorial Primes</a>.
%H Joe McLean, <a href="http://web.archive.org/web/20091027034731/http://uk.geocities.com/nassarawa%40btinternet.com/probprim2.htm">Interesting Sources of Probable Primes</a>
%t MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
%t Select[Range[1000], (x = MultiFactorial[#, 4] - 4; x > 0 && PrimeQ[x]) &]
%Y Cf. A007662, A283553.
%K nonn
%O 1,1
%A _Robert Price_, Nov 06 2019