hi,

could anyone help me with the following problem?

find the number of pairs (x,y) for which 1<=x,y<=10^7 and gcd(x,y) = x xor y

here are my thoughts: we can let x=da and y=db for coprime a,b then we must have a XOR b = 1 i.e. a and b are consecutive integers. how do we proceed from here

thanks!