  We study pairwise entanglements in spin-half and spin-one Heisenberg chains
with an open boundary condition, respectively. We find out that the
ground-state and the first-excited-state entanglements are equal for the
three-site spin-one chain. When the number of sites L>3, the concurrences and
negativities display oscillatory behaviors, and the oscillations of the
ground-state and the first-excited-state entanglements are out of phase or in
phase.
