\begin{definition}[Definition:Keith Number]
Let $K \in \Z_{>9}$ be an $n$-digit integer, where $n > 1$.
Let $A = \left({a_1, a_2, \ldots, a_n}\right)$ be the digits of $K$ in order.
Let $F_A$ be the Fibonacci-like sequence on $A$.
Then $K$ is a '''Keith number''' {{iff}} $K$ occurs somewhere in $F_A$.
\end{definition}