Prime Numbers

This month I've been looking at the Collatz conjecture. This is the one where you start from a number, then halve it if it is even or mu...

OK, one more post on the Ulam Spiral. In the last post I mentioned that the half diagonals of the spiral are quadratic polynomials, and ga...

Incidentally, when I am talking about composite numbers as the difference between two squares, I am talking about what is generally known as...

OK, I've done some work on this and I think there are at least a few interesting points that can be made about the Ulam Spiral based on ...

I just want to look at the sequences of composite numbers expressed as the difference between two squares in an Ulam spiral. In this one I...

Nb: the post below was my first attempt at understanding this - there is a more streamlined version here : I've borrowed the image belo...

OK, the thing I want to look at next is the sequences that develop within this grid when we look at N^2 - P^2 for a fixed value of N-P (for ...