Android Question Function for blessing!

Hello friends,

I am trying to find a way to get the sum binary result of checkbox array each time one (or more) array
element is clicked.
e.g.
c(0) = 1, c(1) = 0, c(2) = 1, c(3) = 1... the result is 0xB
Now if c(0) is clicked the result will be 0x3
and so on..

Any help appreciated.