Perform the following calculations and assign to Python variables of the same name

$a=67$

$kB=1\mathrm{.}38{10}^{-23}$

$N=26\mathrm{.}022{10}^{23}$

$T=273\mathrm{.}14$

$pV=NkBT$

einv$2=1-2+\frac{1}{2}(-2{)}^2+\frac{1}{2*3}(-2{)}^3+\frac{1}{2*3*4}(-2{)}^4$