For a recurrence relation an=c1an−1+c2an−2a_n = c_1 a_{n-1} + c_2 a_{n-2}an=c1an−1+c2an−2, if c1=0c_1=0c1=0 and c2=1c_2=1c2=1, what is the sequence?
a0,a1,a0,a1,…a_0, a_1, a_0, a_1, \dotsa0,a1,a0,a1,…
a0,a1,a1,a2,…a_0, a_1, a_1, a_2, \dotsa0,a1,a1,a2,…
a0,a1,2a1,…a_0, a_1, 2a_1, \dotsa0,a1,2a1,…
It is not a valid recurrence.