Hydrogenic radial function

n	R(r)
1	$2\alpha^{3/2}\exp(-\alpha r)$
2	$\frac{1}{2\sqrt 2}\alpha^{3/2}(2-\alpha r)\exp(-\alpha r /2)$
3	${\sqrt \frac{4}{27}}\alpha^{3/2}(1-2\alpha r/3+2\alpha^2 r^2/27)\exp(-\alpha r /3)$