OFFSET
1,1
COMMENTS
According to the conjecture in A237413, this sequence should have infinitely many terms.
LINKS
Zhi-Wei Sun, Table of n, a(n) for n = 1..10000
Z.-W. Sun, Problems on combinatorial properties of primes, arXiv:1402.6641, 2014
EXAMPLE
a(1) = 2 since 2^2 - 2 = 2 and prime(2)^2 - 2 = 3^2 - 2 = 7 are both prime.
MATHEMATICA
p[n_]:=PrimeQ[n^2-2]
n=0; Do[If[p[Prime[k]]&&p[Prime[Prime[k]]], n=n+1; Print[n, " ", Prime[k]]], {k, 1, 1000}]
Select[Prime[Range[1200]], AllTrue[{#^2-2, Prime[#]^2-2}, PrimeQ]&] (* Harvey P. Dale, Apr 06 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Zhi-Wei Sun, Feb 07 2014
STATUS
approved