A288717 Primes of the form k!7+1, where k!7 is the septuple factorial number (A114799).

2, 3, 5, 7, 19, 31, 61, 79, 12241, 19801, 29641, 76561, 379441, 2016841, 2756161, 1838865601, 4150656721, 337767408001, 956960801281, 21617114112001, 1534815101952001, 9590944392057601, 30891838760640001, 119715577952256001, 767275551364608001

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..46

Henri& Renaud Lifchitz, PRP Records.Search for n!7+1.

Joe McLean, Interesting Sources of Probable Primes

OpenPFGW Project, Primality Tester

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 7] + 1, {i, 0, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n, 1, -7]+1, {n, 100}], PrimeQ] (* Harvey P. Dale, Dec 23 2022 *)

Crossrefs

Cf. A156165.

Sequence in context: A048419 A087562 A154525 * A144561 A215156 A065724

Adjacent sequences: A288714 A288715 A288716 * A288718 A288719 A288720

Keyword

nonn

Author

Robert Price, Jun 13 2017

Status

approved