OFFSET
1,1
COMMENTS
All terms are == 1 mod 4, hence in all cases p+3 is divisible by 4 (and is not squarefree).
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Prime[Range[1000]], SquareFreeQ[# + 1] && SquareFreeQ[# + 2] &]
PROG
(Magma) [p: p in PrimesUpTo(1500) | IsSquarefree(p+1) and IsSquarefree(p+2)]; // Vincenzo Librandi, Feb 09 2016
(PARI) isok(p) = isprime(p) && issquarefree(p+1) && issquarefree(p+2); \\ Michel Marcus, Apr 01 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Feb 08 2016
STATUS
approved