To date the computation of regular confluent hypergeometric function is slow for large |az| values. I found that Matlab does not perform well when a or z is large. The only program I know of, on Mathworks was a normal series expansion of the 1F1, which I think is not actually a good method, as it requires alot of terms to be added up. So I  cant actually see that Matlab gives more accurate or even faster results than Maple or even Mathematica, anyway

What I do want to know is where does one get the closed form solution Robert gave as

I am still a masters student and still learning and I can't seem to see or find an article where that closed form solution are derived from. Probably missing something since I dont see any the values of a or b in it, maybe already incorporated?

Can somebody help.

And dont worry next year a new method will be suggested for solving the 1F1(a,b,c) for all parameters a, b, and c!  :)

Cheers.