To start off this thread, I'm using my online definition for science (which can be adjusted since science is fluid):
the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.
Let's look over the simplest branch of math: basic algebra which has about a dozen axioms. Those axioms have been built up through induction (e.g. the commutative laws of addition and multiplication). They've been studied through observation and experiment. And theorems have been built up through deduction.
Patterns do lead to theorems that can be proven algebraically. So e.g. we have:
1 x 3 + 1 = 2 x 2
2 x 4 + 1 = 3 x 3
3 x 5 + 1 = 4 x 4
4 x 6 + 1 = 5 x 5...
So through observation and experiment, I see that the pattern on the left side of the equal sign generates squared numbers on the right side of the equal sign and I can prove this in general using algebra which means this is a theorem.
This is a particular example and there are many examples from many branches of math so yes, I do regard math as a science.
Any thoughts to add to this?
PhilX