Ackerman Function

def. Ackerman Function. The Ackerman function satisfies the following recurrence relations:

1. $A(k,n)=A(k-1,A(k,n-1))$
2. $A(k,1)=2$
3. $A(1,n)=2n$

• Example:
  • $A(2,n)=A(1,A(2,n-1))=\cdots =A(1,A(1,\dots A(2,1)))=2^n$
  • $A(3,n)=2\uparrow n$

Properties §

• Grows really fast
• Appears in Limits of Math and Computing