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A268614
Primes p such that p + 1 and p + 2 are squarefree.
1
5, 13, 29, 37, 41, 101, 109, 113, 137, 157, 181, 193, 229, 257, 281, 317, 353, 389, 397, 401, 409, 433, 461, 509, 541, 569, 613, 617, 641, 653, 661, 677, 757, 761, 769, 797, 821, 829, 857, 877, 937, 941, 977, 1009, 1021, 1093, 1109, 1117, 1129, 1153, 1193
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
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
Intersection of A049097 and A049233.
Sequence in context: A133204 A207040 A309588 * A152658 A347836 A100877
KEYWORD
nonn
AUTHOR
Zak Seidov, Feb 08 2016
STATUS
approved