Yea, 51, but with n = 40 you are already at the number of atoms in the universe ~10^80. That would leave around 11^50 calculations per atoms in the universe, at 1,000,000 Ghz you are talking about 10^32 seconds which ~ 3 * 10^24 years. Or 10^15 = (1,000,000,000,000,000) times the current age of the universe.
For any calculable n, n^n is less than n^50. Ok, if computing power doubled every year, for the next 200 years we would still not be able do 50^50 calculations. But in 250 years of doubling each year it would be easy.
For any calculable n, n^n is less than n^50. Ok, if computing power doubled every year, for the next 200 years we would still not be able do 50^50 calculations. But in 250 years of doubling each year it would be easy.