Problem 224
Almost right-angled triangles II

Let us call an integer sided triangle with sides a ≤b ≤c barely obtuse if the sides satisfy
a2 + b2 = c2 - 1.

How many barely obtuse triangles are there with perimeter ≤ 75,000,000?

These problems are part of Project Euler and are licensed under CC BY-NC-SA 2.0 UK