Fast Growing Hierarchy Calculator High Quality -

The (FGH) is a family of functions ( f_\alpha : \mathbbN \to \mathbbN ) indexed by ordinals ( \alpha ). It is central to proof theory and computational googology, as it provides a scale for comparing the growth rates of functions.

that can display fundamental sequences and calculate both FGH and SGH (Slow-Growing Hierarchy) up to high ordinals like Rathjen's Quick Reference: How FGH Grows fast growing hierarchy calculator high quality