User blog comment:Ikosarakt1/Another research in comparisons between FGH and SGH/@comment-10429372-20131030175218

The problem is that you can't increase the n in ga(n). So gtheta(w+1)(n) = gtheta(w,theta(w,...))(n) = gtheta(n,theta(n,...))(n) = gtheta(n+1)(n) ~ fw(n+1)

And gtheta(w2)(n) ~ fw(2n)

And gtheta(w^2)(n) ~ fw(n^2)