OFFSET
1,1
COMMENTS
The corresponding n are in A199191.
The next term -- a(10) -- has 152 digits. - Harvey P. Dale, May 28 2015
FORMULA
Primes in A198410.
MATHEMATICA
a={}; Do[p=( (3^(n-1) + 1)^3 -1)/3^n; If[PrimeQ[p], AppendTo[a, p]], {n, 10^2}]; Print[a];
Select[Table[3^(2n-3)+3^(n-1)+1, {n, 100}], PrimeQ] (* Harvey P. Dale, May 28 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Nov 03 2011
STATUS
approved