There are two identities known as Catalan's identity.
The first is
where is a Fibonacci number. Letting gives Cassini's Identity.
The second is the trivariate identity on partition of cubes into a sum of three squares given by
There are two identities known as Catalan's identity.
The first is
where is a Fibonacci number. Letting gives Cassini's Identity.
The second is the trivariate identity on partition of cubes into a sum of three squares given by
Weisstein, Eric W. "Catalan's Identity." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CatalansIdentity.html