A329166 Numbers k such that k![4] - 16 is prime, where k![4] = A007662(k) = quadruple factorial.

7, 9, 13, 15, 17, 29, 31, 35, 39, 105, 109, 147, 173, 239, 287, 293, 505, 711, 837, 947, 1015, 1025, 1977, 2917, 4035, 4935, 5935, 7693, 10911, 11367, 12029, 14155, 15221, 17921, 17961, 20521, 23053, 32821, 45147, 45351, 68057, 78315

Offset

1,1

Comments

a(43) > 10^5.

The first 5 primes associated with this sequence are: 5, 29, 569, 3449, 9929.

Links

Table of n, a(n) for n=1..42.

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C. Caldwell and H. Dubner (Eds): The top ten prime numbers: from the unpublished collections of R. Ondrejka (May 2001), Table 21 F, p. 75.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

Mathematica

MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[1000], (x = MultiFactorial[#, 4] - 16; x > 0 && PrimeQ[x]) &]

Crossrefs

Cf. A007662, A283553.

Sequence in context: A051913 A180645 A196091 * A222945 A129069 A258616

Adjacent sequences: A329163 A329164 A329165 * A329167 A329168 A329169

Keyword

nonn

Author

Robert Price, Nov 06 2019

Status

approved