%I #3 Mar 31 2012 12:35:21
%S 1,1,2,5,11,46,267,1767,17587,243760,4437947,112889388,3947281130,
%T 187476143214,12242161648191,1095392081180001,134002137948473492,
%U 22462563463091094957,5156385913433257078626
%N Number of planar n X n X n binary triangular grids with every one adjacent to exactly 2 other ones.
%K nonn
%O 0,3
%A _R. H. Hardin_ Jan 04 2009