A062551 Primes of the form 3*k! + 1.

7, 19, 73, 2161, 15121, 1088641, 10886401, 18681062401, 77556050216654929920001, 46533630129992957952000001, 789392510801080590501654036480000001

Offset: 1

Author

Jason Earls, Jul 10 2001

Keywords

• nonn

Links

• Harry J. Smith, Table of n, a(n) for n=1,...,15

Crossrefs

Cf. A076679, A173324.

Programs

Mathematica

lst={};Do[p=3*n!+1;If[PrimeQ[p],AppendTo[lst,p]],{n,0,5!}];lst (* Vladimir Joseph Stephan Orlovsky, Jan 28 2009 *)
Select[3*Range[40]! +1,PrimeQ] (* Harvey P. Dale, Jul 20 2018 *)

PARI

for(n=1,40, if(isprime(3*n!+1),print(3*n!+1)))

PARI

{ n=0; for (m=0, 10^5, if(isprime(a=3*m! + 1), write("b062551.txt", n++, " ", a); if (n==15, break)) ) } \\ Harry J. Smith, Aug 08 2009

Formula

a(n) = A173324(A076679(n)). - Elmo R. Oliveira, Apr 17 2025