Natural number which can be expressed as sum of two perfect squares in two different ways? Ramanujan's number is $1729$ which is the least natural number which can be expressed as the sum of two perfect cubes in two different ways. But can we find a number which can be expressed as the sum of two perfect squares in two different ways. One example I got is $50$ which is $49+1$ and $25+25$. But here second pair contains same numbers. Does any one have other examples ? 

The Brahmagupta–Fibonacci identity says that every product of two sums of two squares is a sum of two squares in two different ways:
\begin{align}
(a^2+b^2)(c^2+d^2) & = (ac+bd)^2 + (ad-bc)^2 \\[6pt]
& = (ac-bd)^2 + (ad+bc)^2
\end{align}
For example:
\begin{align}
(2^2+3^2)(1^2+7^2) & = 23^2 + 11^2 \\[6pt]
& = 19^2 + 17^2
\end{align}
