A288885 Primes of the form k!3 + 3^9, where k!3 is the triple factorial number (A007661).

19687, 19763, 19963, 20563, 32003, 229123, 4208483, 24364003, 72642189283, 2324549446883, 5577337931669523683, 38900816605808456499219683, 26070192823309041523916819683

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..18

Henri& Renaud Lifchitz, PRP Records.Search for n!3+3^9.

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, 3] + 3^9, {i, 0, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n, 1, -3]+19683, {n, 100}], PrimeQ] (* Harvey P. Dale, Sep 18 2023 *)

Crossrefs

Cf. A265378.

Sequence in context: A352037 A321813 A081866 * A253493 A253500 A253454

Adjacent sequences: A288882 A288883 A288884 * A288886 A288887 A288888

Keyword

nonn

Author

Robert Price, Jun 18 2017

Status

approved