100 for m = 0 to 4
110   print using "###";m;
120   for n = 0 to 6
130     if m = 4 and n = 1 then goto 160
140     print using "######";ack(m,n);
150   next n
160   print
170 next m
180 end
190 sub ack(m,n)
200   if m = 0 then ack = n+1
210   if m > 0 and n = 0 then ack = ack(m-1,1)
220   if m > 0 and n > 0 then ack = ack(m-1,ack(m,n-1))
230 end sub