Perhaps this could be included on the site. Perhaps it already is although I have yet to find it. I am a US secondary math teacher. Steve Conn Plus is a free web-site with no subscription requirements. It publishes 3 times a year.
Back issues are always accessible, so the site is building up into a useful resource.
We can't give a blanket permission for all pictures and puzzles because some material is used with permission from elsewhere. However, feel free to ask about specific items you'd like to use, and we'll give you a yes or no. We would also like confirmation that the school web site is not being used for commercial purposes. Summing the squares I stumbled across your web site whilst trying to find an answer to the following problem. Since the differences between successive totals are the squares of the integers, my guess is that quadratics must come into it somewhere.