If an Even number could be expressed in the form a² + b² . And if there exits two other numbers m,n such that
a² + b² = m² + n²
then , my question is
is there any relation between (a,b) and (m,n) apart from a² + b² = m² + n² ??
There is an interesting theorem that may or may not help . . .
If a number is of the form , the product of two sums of squares,
. . then can be expressed as the sum of two squares in two ways.