A288410 Primes of the form k!2+128, where k!2 is the double factorial number (A006852).

131, 233, 34459553, 654729203, 191898783962510753, 563862029680583509947947003, 2980227913743310874726229193922003

Offset: 1

Author

Robert Price, Jun 08 2017

Keywords

• nonn

Comments

The next term (a(8)) has 147 digits. - Harvey P. Dale, Apr 09 2020

Links

• Robert Price, Table of n, a(n) for n = 1..8
• Henri& Renaud Lifchitz, PRP Records.Search for n!2+128.
• Joe McLean, Interesting Sources of Probable Primes
• OpenPFGW Project, Primality Tester

Crossrefs

Cf. A076194.

Programs

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 2] + 128, {i, 0, 100}], PrimeQ[#]&]
Select[Range[100]!!+128,PrimeQ] (* Harvey P. Dale, Apr 09 2020 *)