WolframAlpha results for logic statement input
There are only 256 possible boolean operations with three inputs, because there are only 256 different ways you can put T's and F's in the result column of the truth table. 

If you look at your truth table, and consider the result column. Instead of T and F, write the results as 1 and 0. Now consider that column of numbers as a binary number. It's value is 

128 + 64 + 32 + 8 = 232