Abstract
We find an upper bound for the ℓp norm of the n×n matrix whose ij entry is (i,j)s/[i,j]r, where (i,j) and [i,j] are the greatest common divisor and the least common multiple of i and j and where r and s are real numbers. In fact, we show that if r>1/p and s<r−1/p, then ‖((i,j)s/[i,j]r)n×n‖p<ζ(rp)2/pζ(rp−sp)1/p/ζ(2rp)1/p for all positive integers n, where ζ is the Riemann zeta function.