  We prove a quantum query lower bound \Omega(n^{(d+1)/(d+2)}) for the problem
of deciding whether an input string of size n contains a k-tuple which belongs
to a fixed orthogonal array on k factors of strength d<=k-1 and index 1,
provided that the alphabet size is sufficiently large. Our lower bound is tight
when d=k-1.
  The orthogonal array problem includes the following problems as special
cases: k-sum problem with d=k-1, k-distinctness problem with d=1, k-pattern
problem with d=0, (d-1)-degree problem with 1<=d<=k-1, unordered search with
d=0 and k=1, and graph collision with d=0 and k=2.
