The Leonardo numbers are a sequence of numbers given by the recurrence: L(n) = \begin{cases} 1 & \mbox{if } n = 0 \\ 1 & \mbox{if } n = 1 \\ L + L + 1 & \mbox{if } n > 1 \\ \end{cases} Edsger W. Dijkstra used them as an integral part of his... Wikipedia