I'am reading paper
HE L, Jiao X X, Zhou X C: $On\ almost\ complex\ curves\ and\ Hopf\ hypersurfaces\ in\ the\ nearly\ K\ddot{a}hler\ 6-sphere, $ Sci China Math, 2014. 57: 1045-1056, doi:10.1007/s11425-014-4777-3
I don't know how to get this formula (3.4) and (3.5) for The mean curvature H and the scalar curvature ρ of tubular hypersurface $M_r ⊂ S^6(1)$?
\begin{align} &H=\frac{(2+5(x_1^2+x_2^2)\lambda^2)\cot\ r-3\cot^3\ r}{5(\cot^2\ r-(x_1^2+x_2^2)\lambda^2)}\dot{\gamma}_\eta(r),\\[0.1cm] &\rho=20+\frac{2-(12+20(x_1^2+x_2^2)\lambda^2)\cot^2\ r+6\cot^4\ r}{\cot^2\ r-(x_1^2+x_2^2)\lambda^2}. \end{align}
Did anyone see calculations for this in some paper or how to get this formulas?