elements.nCr where n=10 and select odd number of set=(1,3,5,7,9)
set of 1 element select from 10 number=10C1
set of 1 element select from 10 number=10C3
set of 1 element select from 10 number=10C5
set of 1 element select from 10 number=10C7
set of 1 element select from 10 number=10C9
10C1 + 10C3 + 10C5 + 10C7 + 10C9 = 512.