English

A fast recurrence for Fibonacci and Lucas numbers

Number Theory 2021-12-22 v1 Discrete Mathematics

Abstract

We derive the double recurrence en=12(an1+5bn1);fn=12(an1+bn1)e_n = \frac{1}{2}(a_{n-1}+5b_{n-1}); f_{n} = \frac{1}{2}(a_{n-1}+b_{n-1}) with e0=2;f0=0e_0=2;f_0=0 for the Fibonacci numbers, leading to an extremely simple and fast implementation. Though the recurrence is probably not new, we have not been able to find a reference for it.

Keywords

Cite

@article{arxiv.2112.10895,
  title  = {A fast recurrence for Fibonacci and Lucas numbers},
  author = {Jeroen van de Graaf},
  journal= {arXiv preprint arXiv:2112.10895},
  year   = {2021}
}