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A120068
Numbers n such that n-th prime + 1 is squarefree.
1
1, 3, 6, 10, 12, 13, 18, 21, 26, 29, 30, 33, 37, 40, 42, 44, 50, 55, 59, 60, 65, 66, 71, 74, 77, 78, 79, 80, 82, 84, 88, 89, 97, 100, 104, 110, 112, 113, 116, 119, 121, 122, 123, 127, 130, 134, 135, 136, 139, 142, 145, 147, 148, 151, 158, 159, 160, 165, 168, 169, 172
OFFSET
1,2
LINKS
FORMULA
a(n)=primepi(A049097(n))
MATHEMATICA
Select[Range[200], SquareFreeQ[Prime[#]+1]&] (* Harvey P. Dale, Sep 07 2012 *)
CROSSREFS
Cf. A049097.
Sequence in context: A261662 A345915 A050107 * A015875 A301285 A310042
KEYWORD
nonn
AUTHOR
Zak Seidov, Aug 15 2006
STATUS
approved