  We show that the 3-block of the sporadic simple Janko group J_4 with defect
group C_3 x C_3, and the principal 3-block of the alternating group A_8 are
Puig equivalent, answering a question posed in earlier work of
Koshitani-Kunugi-Waki. To accomplish this, we apply computational techniques,
in particular an explicit version of the Brauer construction.
