%I #8 Jan 24 2019 10:45:16
%S 0,0,128,6912,301056,13107200,604661760,30105600000,1625414303744,
%T 95105071448064,6014219459788800,409597814515957760,
%U 29930757120000000000,2338124811342685667328,194579196865600687702016,17194638200501483392204800,1608612930338829120118456320,158879430213632000000000000000
%N a(n) = (n - 3)^2*(n - 4)*2^n*n^(n-5).
%H Andrei Asinowski, Gill Barequet, Ronnie Barequet, Gunter Rote, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL15/Barequet/barequet2.html">Proper n-Cell Polycubes in n-3 Dimensions</a>, J. Int. Seq. 15 (2012) #12.8.4.
%Y Cf. A232994.
%K nonn
%O 3,3
%A _N. J. A. Sloane_, Dec 16 2013