A288446 Numbers k such that k!6 + 24 is prime, where k!6 is the sextuple factorial number (A085158 ).

5, 7, 11, 19, 23, 29, 53, 67, 71, 79, 109, 121, 275, 707, 725, 1345, 1961, 2221, 2477, 2765, 5557, 5779, 7423, 11587, 22495, 25063, 28795, 43783

Offset

1,1

Comments

Corresponding primes are: 29, 31, 79, 1753, 21529, 623669, 2229272062349, ...

a(29) > 50000.

Terms > 29 correspond to probable primes.

Links

Table of n, a(n) for n=1..28.

Henri & Renaud Lifchitz, PRP Records. Search for n!6+24.

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

Example

11!6 + 24 = 11*5 + 24 = 79 is prime, so 11 is in the sequence.

Mathematica

MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 24] &]

Crossrefs

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

Sequence in context: A118386 A240849 A116641 * A213981 A273048 A240621

Adjacent sequences: A288443 A288444 A288445 * A288447 A288448 A288449

Keyword

nonn,more

Author

Robert Price, Jun 09 2017

Status

approved