10. Find the first six terms of the sequence defined by each
of these recurrence relations and initial conditions.
a) $a_n = -2a_{n-1}$, $a_0 = -1$
b) $a_n = a_{n-1} - a_{n-2}$, $a_0 = 2$, $a_1 = -1$
c) $a_n = 3a_{n-1}^2$, $a_0 = 1$
d) $a_n = na_{n-1} + a_{n-2}^2$, $a_0 = -1$, $a_1 = 0$
e) $a_n = a_{n-1} - a_{n-2} + a_{n-3}$, $a_0 = 1$, $a_1 = 1$, $a_2 = 2$
