A288376 Primes of the form k!2+2, where k!2 is the double factorial number (A006852).

3, 5, 17, 107, 947, 13749310577, 316234143227, 213458046676877, 495179769008019818390136611716089140627, 13114900840751548972796135496384318234575359262373046877, 28352254429826839019508359891905756542124154226667992913078222750278633810791015627

Offset: 1

Author

Robert Price, Jun 08 2017

Keywords

• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..12
• Henri& Renaud Lifchitz, PRP Records.Search for n!2+2.
• Joe McLean, Interesting Sources of Probable Primes
• OpenPFGW Project, Primality Tester

Crossrefs

Cf. A076815.

Programs

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 2] + 2, {i, 0, 100}], PrimeQ[#]&]