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A329183
Numbers k such that k![4] - 512 is prime, where k![4] = A007662(k) = quadruple factorial.
0
13, 15, 17, 19, 21, 23, 25, 35, 39, 47, 67, 71, 89, 93, 113, 153, 163, 185, 201, 267, 427, 491, 871, 1645, 3075, 3351, 3435, 5385, 7893, 10649, 15597, 44641, 50039, 57269, 67647, 83061, 89717
OFFSET
1,1
COMMENTS
a(38) > 10^5.
The first 5 primes associated with this sequence are: 73, 2953, 9433, 65323, 208333.
LINKS
MATHEMATICA
MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[1000], (x = MultiFactorial[#, 4] - 512; x > 0 && PrimeQ[x]) &]
CROSSREFS
Sequence in context: A180642 A176717 A070603 * A302440 A031060 A120129
KEYWORD
nonn
AUTHOR
Robert Price, Nov 07 2019
STATUS
approved