proposed

approved

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proposed

Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n!6+69&amp;action=Search">PRP Records. Search for n!6+9.</a>

proposed

editing

editing

proposed

allocated for Robert PriceNumbers k such that k!6 + 9 is prime, where k!6 is the sextuple factorial number (A085158 ).

2, 4, 14, 28, 34, 46, 50, 52, 86, 100, 106, 140, 166, 170, 208, 242, 338, 344, 412, 1360, 2024, 2948, 3650, 5608, 5744, 7618, 8410, 8834, 11872, 12514, 13636, 18742, 20846, 29750, 31312

1,1

Corresponding primes are: 11, 13, 233, 394249, 13404169, 24663654409, 311607296009, ...

a(36) > 50000.

Terms > 50 correspond to probable primes.

Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n!6+6&amp;action=Search">PRP Records. Search for n!6+9.</a>

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>

OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>

14!6 + 9 = 14*8*2 + 9 = 233 is prime, so 14 is in the sequence.

MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];

Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 9] &]

Cf. A007661, A037082, A084438, A123910, A242994.

allocated

nonn,more,new

Robert Price, Jun 05 2017

approved

editing

allocated for Robert Price

allocated

approved