A289857 Primes of the form k!2 - 512, where k!2 is the double factorial number (A006882).

433, 9883, 13749310063, 316234142713, 25373791335626257947657608863, 7297912393562140321551086320493608726062890113, 79777941814291672401518892224505807820921910393015244140113

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..10

Henri and Renaud Lifchitz, PRP Records.Search for n!2-512.

Joe McLean, Interesting Sources of Probable Primes.

OpenPFGW Project, Primality Tester.

Formula

a(n) = A006882(A258452(n)) - 512. - Elmo R. Oliveira, Apr 14 2025

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 2] - 512, {i, 9, 100}], PrimeQ[#]&]

Crossrefs

Cf. A006882, A258452.

Sequence in context: A142539 A059665 A059664 * A198450 A241925 A108832

Adjacent sequences: A289854 A289855 A289856 * A289858 A289859 A289860

Keyword

nonn

Author

Robert Price, Jul 13 2017

Status

approved