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A156167 Numbers n such that n![7]-1 is prime (where n![7] = A114799(n) = septuple factorial).

%I A156167 #18 Apr 03 2023 10:36:11
%S A156167 3,4,6,8,9,10,11,12,14,17,20,24,30,31,32,46,52,54,59,98,104,143,145,
%T A156167 160,174,198,199,202,212,215,254,371,382,452,674,739,959,1249,1657,
%U A156167 2291,2553,2650,3562,3727,3853,4389,4604,5449,5659,6026,6878,7900,9564,10150,12444,13321,22642,24014,26598,27430,31386,40707,43328,45811
%N A156167 Numbers n such that n![7]-1 is prime (where n![7] = A114799(n) = septuple factorial).
%C A156167 a(65) > 50000. - _Robert Price_, Sep 09 2012
%H A156167 C. Caldwell, 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The top ten prime numbers: from the unpublished collections of R. Ondrejka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 A156167 Ken Davis, <a href="http://mfprimes.free-dc.org">Status of Search for Multifactorial Primes</a>.
%H A156167 Ken Davis, <a href="http://mfprimes.free-dc.org/mfdata/f07m.html">Results for n!7-1.</a>
%t A156167 MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
%t A156167 Select[Range[0, 1000], PrimeQ[MultiFactorial[#, 7] - 1] & ] (* _Robert Price_, Apr 19 2019 *)
%o A156167 (PARI) mf(n,k=7)=prod(i=0,(n-2)\k,n-i*k)
%o A156167 for( n=1,9999, ispseudoprime(mf(n)-1) & print1(n","))
%Y A156167 cf. A156165, A051592, A085149, A085147, A084438, A007749, A002982.
%K A156167 nonn
%O A156167 1,1
%A A156167 _M. F. Hasler_, Feb 10 2009
%E A156167 a(43)-a(64) from _Robert Price_, Sep 09 2012