On Sequences $G_n$ satisfying $G_n=(d+2)G_{n-1} - G_{n-2}$
J. Integer Seq. 10(8), Article 07.8.1, 10 p., electronic only (2007)
Summary
Summary: In this note, we study a class of sequences $G_{n}$ satisfying $G_{n} = (d+2)G_{n-1} - G_{n-2}$. Note that the Fibonacci numbers $G_{n} = F_{2n}, n >1$ and $G_{n} = F_{2n+1}, n > 0$ occur when $d=1$ with suitable initial conditions. We present a general interpretation for this class of sequences in terms of ordered trees which we count by nodes and outdegrees. Further more, several other related integer sequences are also studied.