a) D={1, 2, 4.}
b) D={1, 2, 5, 10.}
c) D={1, 2, 3, 6, 9, 18.}
d) D={1, 31.}
e) D={1, 3, 5, 9, 15, 45.}
f) D={1, 2, 4, 7, 8, 14, 28, 56.}
g) D={1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72.}
h) D={1, 2, 3, 4, 6, 7, 12, 21, 28, 42, 84.}
i) D={1, 2, 4, 5, 10, 20, 25, 50, 100.}