tower of hanoi

describe the strategy and the formula for the tower of hanoi puzzle ::

basically ,
the objective of the puzzle was to move all the pieces from the left pole
to the right in the least possible amount of steps ..
as you can see , i have completed it in 36
while the minimum number of steps is actually 31 ..
anyhow , basically i just used trial and error and in the end ,
somehow , got all the pieces onto the right side ..
the most important thing is moving the top pieces
but not blocking or preventing the movemnet of the last piece ..

my strategy was moving the first piece to the middle pole
( in order to not block the other pieces from moving there )
then going back and forth and stacking the pieces in the middle
so that i could move the last piece to the third pole