  We show that there exist knots K in S^3 with g(E(K))=2 and g(E(K#K#K))=6.
Together with Theorem~1.5 of [1], this proves existence of counterexamples to
Morimoto's Conjecture (Conjecture 1.5 of [2]). This is a special case of
arxiv.org/abs/math.GT/0701765
  [1] Tsuyoshi Kobayashi and Yo'av Rieck. On the growth rate of the tunnel
number of knots. J. Reine Angew. Math., 592:63--78, 2006.
  [2] Kanji Morimoto. On the super additivity of tunnel number of knots.Math.
Ann., 317(3):489--508, 2000.
