Leonardo number
Appearance
The Leonardo numbers are a sequence of numbers given by the recurrence:
Edsger W. Dijkstra[1] used them as an integral part of his smoothsort algorithm,[2] and also analyzed them in some detail.[3]
Values
The first few Leonardo numbers are
Relation to Fibonacci numbers
The Leonardo numbers are related to the Fibonacci numbers by the relation .
From this relation it is straightforward to derive a closed-form expression for the Leonardo numbers, analogous to Binet's formula for the Fibonacci numbers:
where the golden ratio and are the roots of the quadratic polynomial .
References
- ^ "E.W.Dijkstra Archive: Fibonacci numbers and Leonardo numbers. (EWD 797)". www.cs.utexas.edu. Retrieved 2020-08-11.
- ^ Dijkstra, Edsger W. Smoothsort – an alternative to sorting in situ (EWD-796a) (PDF). E.W. Dijkstra Archive. Center for American History, University of Texas at Austin. (transcription)
- ^ "E.W.Dijkstra Archive: Smoothsort, an alternative for sorting in situ (EWD 796a)". www.cs.utexas.edu. Retrieved 2020-08-11.
External links
- OEIS sequence A001595