C

n=2.5538+0.0342*pow(x,-2)

Python

n=2.5538+0.0342*x**-2

Fortran

n=2.5538+0.0342*x**-2

MATLAB

n=2.5538+0.0342.*x.^-2

LaTeX

n=2.5538+0.0342λ^{-2}