A288715 Primes of the form k!8+1, where k!8 is the octuple factorial number (A114800).

2, 3, 5, 7, 26881, 55441, 96909121, 132843110401, 48704929136641, 152349556104345601, 1397121162877440001, 383414179456168545484801, 81419177249980419349301811609600001, 13189906714496827934586893480755200001

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..21

Henri& Renaud Lifchitz, PRP Records.Search for n!8+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, 8] + 1, {i, 0, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n, 1, -8]+1, {n, 200}], PrimeQ] (* Harvey P. Dale, Dec 26 2022 *)

Crossrefs

Cf. A204661.

Sequence in context: A252357 A037948 A007659 * A208361 A145380 A136740

Adjacent sequences: A288712 A288713 A288714 * A288716 A288717 A288718

Keyword

nonn

Author

Robert Price, Jun 13 2017

Status

approved