Category:Definitions/Keith Numbers

This category contains definitions related to Keith Numbers.
Related results can be found in Category:Keith Numbers.

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 if and only if $K$ occurs somewhere in $F_A$.