r(x) = (-1+sqrt(2*floor((x-1)/3)-1))/2
rp(x) = floor(r(x))+1
R(x) = sqrt((2*rp(x)*(rp(x)+1)+1)/pi)
NR(x) = pi*R(x)**2 + 2*sqrt(2)*pi*R(x)


R(x) =  (sqrt(2)*pi+sqrt(2*pi*pi+pi+floor((x-1)/3)))/pi
Rp(x) = floor(R(x)) + 1
NR(x) = pi*Rp(x)**2 + 2*sqrt(2)*pi*Rp(x)
