10   X=3:P=27
20   while X<1000000
30     Y=log(P-17)/log(2)
35     Yr=int(Y+0.5)
40     if abs(Y-Yr)<0.00000001 then print x,y
80     X=X+1:P=P*3
90   wend

finds only x=4, y=6, before overflowing the capacity of the log function at x = 5432.