User blog comment:AJZajac/How fast does this sequence grow (problem in ordinal arithmetic)?/@comment-31607182-20171212204502/@comment-30754445-20171212205622

It's not "exactly", because fω2+1(n) uses the final value of n for all the steps.

The exact equation in your version would be:

a(n) = fω2n(1)

While the FGH function is defined as:

fω2+1(n) = fω2n(n)