A329176 Numbers k such that k![4] - 128 is prime, where k![4] = A007662(k) = quadruple factorial.

11, 13, 17, 19, 25, 27, 29, 41, 47, 61, 75, 113, 181, 251, 287, 339, 521, 533, 573, 687, 739, 1015, 1243, 1811, 2073, 2851, 2939, 3421, 4055, 4211, 4477, 5219, 6151, 8851, 9251, 14219, 17123, 21703, 24313, 25053, 28811, 33065, 49305, 50775, 52693, 69805, 82077, 87771

Offset

1,1

Comments

a(49) > 10^5.

The first 5 primes associated with this sequence are: 103, 457, 9817, 65707, 5220997.

Links

Table of n, a(n) for n=1..48.

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C. Caldwell and H. Dubner (Eds): The top ten prime numbers: from the unpublished collections of R. Ondrejka (May 2001), Table 21 F, p. 75.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] - 128; x > 0 && PrimeQ[x]) &]
Select[Range[10, 90000], PrimeQ[Times@@Range[#, 1, -4]-128]&] (* Harvey P. Dale, May 13 2022 *)

Crossrefs

Cf. A007662, A283553.

Sequence in context: A293662 A244913 A098415 * A067283 A052259 A103900

Adjacent sequences: A329173 A329174 A329175 * A329177 A329178 A329179

Keyword

nonn

Author

Robert Price, Nov 07 2019

Status

approved