Question 91
Call a positive integer one-full if it satisfies the following criteria:
a. Every digit is either $0$, $1$, or $2$.
b. Out of every two consecutive digits, at least one of them is a $1$.
For $n \geq 2$, calculate the number of $n$-digit one-full numbers. (Numbers beginning with the digit $0$ are not allowed.)
a. Every digit is either $0$, $1$, or $2$.
b. Out of every two consecutive digits, at least one of them is a $1$.
For $n \geq 2$, calculate the number of $n$-digit one-full numbers. (Numbers beginning with the digit $0$ are not allowed.)