Helium excitiation energies

[Paygan]

I'm looking for the excitation energy for the first excited state of Helium. If anyone has the value handy I'd appreciate it (references would be even better.) I've been searching but I can't find it anywhere.

Thanks

EDIT: I ended up working it out via the Helium emission spectra.
1s2 -> 1s2s
[lambda] = 584.33 angstroms
=> E=21.36eV