OFFSET
1,5
EXAMPLE
a(1)=1`because 1*sqrt(1-1)<(prime 2)<=(1+1)*sqrt(1),
a(2)=1 because 2*sqrt(2-1)<(prime 3)<=(2+1)*sqrt(2).
MATHEMATICA
Table[PrimePi[(n+1)*Sqrt[n]] - PrimePi[n*Sqrt[n-1]], {n, 100}] (* T. D. Noe, Sep 14 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Sep 07 2011
STATUS
approved