Recurrence relation for number of ternary strings that contain two consecutive zeros
On the link above, how can I use the formula for two consecutive 2s? I'm new to this and I'm not sure if it's valid for either 0s, 1s or 2s or just consecutive 0s.
Second question, regarding this link: Prove sequence with fibonacci recurrence bounded by $(7/4)^n$
is it also possible for n>= 2?
Thank you!