A288448 Numbers k such that k!6 + 32 is prime, where k!6 is the sextuple factorial number (A085158 ).

5, 9, 17, 21, 29, 53, 57, 105, 111, 279, 303, 435, 483, 677, 1049, 1217, 1395, 9651, 26031, 31937

Offset

1,1

Comments

Corresponding primes are: 37, 59, 967, 8537, 623677, 2229272062357, 38661097149707, ...

a(21) > 50000.

Terms > 29 correspond to probable primes.

Links

Table of n, a(n) for n=1..20.

Henri & Renaud Lifchitz, PRP Records. Search for n!6+32.

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

Example

17!6 + 32 = 17*11*5 + 32 = 967 is prime, so 17 is in the sequence.

Mathematica

MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 32] &]

Crossrefs

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

Sequence in context: A273851 A097538 A001771 * A022341 A255651 A216877

Adjacent sequences: A288445 A288446 A288447 * A288449 A288450 A288451

Keyword

nonn,more

Author

Robert Price, Jun 09 2017

Status

approved