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