A288878 Primes of the form k!3 + 3^2, where k!3 is the triple factorial number (A007661).

11, 13, 19, 37, 89, 12329, 209449, 1106569, 24344329, 96342409, 2504902409, 17961239296009, 52580450364682240009, 2295148179742698933452800009, 7825229077844441903818866688000009, 145302140752338100885902776123355299840000009

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..24

Henri& Renaud Lifchitz, PRP Records.Search for n!3+3^2.

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] + 3^2, {i, 0, 100}], PrimeQ[#]&]

Crossrefs

Cf. A247865.

Sequence in context: A167497 A068579 A048519 * A102907 A235479 A089774

Adjacent sequences: A288875 A288876 A288877 * A288879 A288880 A288881

Keyword

nonn

Author

Robert Price, Jun 18 2017

Status

approved