All Square (with thanks to Catriona)

I share my birthday, today, with Catriona, and this is taken from her blog posting today.

This birthday is a square number, with a vaguely biblical ring to it… a source for jubilation, maybe?

It is thirteen years since the last square birthday… the the next will be fifteen into the future (DV, as my grandmother would say).

There are no prizes for working it out, just a little festive arithmetic for you!