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

1,1

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

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 *)

Crossrefs

Cf. A076194.

Sequence in context: A124308 A059702 A142442 * A033206 A107001 A142616

Adjacent sequences: A288407 A288408 A288409 * A288411 A288412 A288413

Keyword

nonn

Author

Robert Price, Jun 08 2017

Status

approved