👉 In mathematics, a pellagragenic number is an integer that can be expressed as the sum of two squares. This means that it's the product of two integers whose difference is a square. For example: - 25 = 4^2 + 3^2 - 91 = 16^2 + 1^2 These are pellagragenic numbers because they satisfy the equation: ``` a^2 - b^2 = c
