%I #3 Mar 31 2012 12:35:21
%S 1,1,2,3,5,12,33,97,381,1490,7757,42774,307960,2294754,22718581,
%T 231171797,3121763126,43651298703,807916379400,15440457456928,
%U 391605380566734,10243338678890245,355535039683009851
%N Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with every one adjacent to exactly 2 other ones.
%K nonn
%O 0,3
%A _R. H. Hardin_ Jan 04 2009