  We prove that the general tensor of size 2^n and rank k has a unique
decomposition as the sum of decomposable tensors if k<= 0.9997 (2^n)/(n+1) (the
constant 1 being the optimal value). Similarly, the general tensor of size 3^n
and rank k has a unique decomposition as the sum of decomposable tensors if k<=
0.998 (3^n)/(2n+1) (the constant 1 being the optimal value).
  Some results of this flavor are obtained for tensors of any size, but the
explicit bounds obtained are weaker.
