OFFSET
1,1
COMMENTS
Subsequence of A122429.
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..30
MATHEMATICA
pnQ[n_]:=Module[{q=4n^2+1, r, s, t}, r=4q^2+1; s=4r^2+1; t=4s^2+1; AllTrue[ {q, r, s, t}, PrimeQ]]; Select[Prime[Range[5678*10^4]], pnQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Aug 08 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Jul 31 2014
STATUS
approved