Describe each of the following sequences, using a recurrence relation together with the initial conditions.

a.) 1,2,4,7,12,20.....

b.) -0.5, 1, -2, 4, -8, ...

c.) 0.03, 0.12, 0.48, 1.92, 7.68, ...

d.) -8, 4, -2, 1, -0.5, 0.25, ...

e.) 1, 2, 5, 12, 29, 70 ...

f.) 1, 5, 11, 19, 29, ...

g.) 2, 3, 9, 31, 284, ...

h.) 2, 3, 5, 14, 69, ...