Ackermann's function

Ackermann's function (ANSI C syntax) :
unsigned int Ack(unsigned int x, unsigned int y){return (x>0)?Ack(x-1,(y>0)?Ack(x,y-1):1):y+1;}
_x \ ^y	0	1	2	3	4	5	6	7	8	9	10	11	12	13	formula for y>0
0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	y+1
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	y+2
2	3	5	7	9	11	13	15	17	19	21	23	25	27	29	2y+3
3	5	13	29	61	125	253	509	1021	2045	4093	8189	16381	32765	65533	2^y+3-3
4	13	65533	¡¿¡¿¡¿												2^Ack(4,y-1)+3-3
5	65533	?!?!?!													Ack(4,Ack(5,y-1))

Click any cell to compute Ackermann's function with JavaScript.
If you get a stack overflow, you may need to refresh the frame.
This shows that a simple recursive function can grow very fast.
Some cells were left empty to preserve the network bandwidth.
Most browsers fail to compute Ack(3,7) and greater or crash.

Modif. 1998-08-19