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Euler found four whole numbers such that the sum of any two of the numbers is a perfect square...
A woman was born in a year that was a square number, lived a square number of years and died in a year that was also a square number. When was she born?
The diagram illustrates the formula: 1 + 3 + 5 + ... + (2n - 1) = nÂ² Use the diagram to show that any odd number is the difference of two squares.