I'm interested in geometry and topology, the Fibonacci numbers and related recurrent sequences, and the history of mathematics, especially ancient mathematics, and in particular ancient Greece and Egypt. There is a lot of geometry and history at my website Tiling Plane and Fancy. I am currently working on a book which will be a collection of mathematical problems related to the Fibonacci numbers. I'm also working on problems in doubly-recursive sequences, their applications, and their relation to Pascal's Triangle I've recently dicsovered that if the generalized Delannoy numbers are taken mod p, wonderful fractal patterns result.
Generalizations of Delannoy and Cross Polytope Numbers, with William Griffiths,
The Fibonacci Quarterly, Volume 55, No. 4, November 2017
A Combinatorial Identity Related to Cross Polytope Numbers, with William Griffiths, The Fibonacci Quarterly, Volume 54, No. 3, August 2016
Proof Without Words: An Infinite Series Using Golden Triangles, The College Mathematics Journal, Vol. 45, No. 2, 2014