I occasionally enjoy recreational mathematics. My first submission to OEIS was in 2004. I have no formal training in number theory or combinatorics, although I've picked up bits and pieces of it on my own over the years. 25 years ago I earned a departmental honor in mathematics from my High School, but haven't had any formal mathematics education subsequent to that.
I also enjoy mathematical artwork and have my own computer software to create beautiful 2D patterns based on simple recursive formulas. It includes the familiar patterns of numbers, modulo a constant divisor N, that can be found in Pascal's Triangle or in Dellanoy Number Arrays, but also several other visual pleasing patterns I've not seen mentioned elsewhere.
Some examples of my art are shared on Pinterest, mixed with mathematical art from other sources:
On Facebook, I have just my own mathematical art shared and more of it:
Let me know if you checked the images out and like them!