1,1

All terms are == 1 mod 4, hence in all cases p+3 is divisible by 4 (and is not squarefree).

Table of n, a(n) for n=1..51.

Select[Prime[Range[1000]], SquareFreeQ[# + 1] && SquareFreeQ[# + 2] &]

(MAGMA) [p: p in PrimesUpTo(1500) | IsSquarefree(p+1) and IsSquarefree(p+2)]; // Vincenzo Librandi, Feb 09 2016

Intersection of A049097 and A049233.

Sequence in context: A224339 A133204 A207040 * A152658 A100877 A261580

Adjacent sequences: A268611 A268612 A268613 * A268615 A268616 A268617

nonn

Zak Seidov, Feb 08 2016

approved