A153957 - OEIS

%I #3 Mar 31 2012 12:35:21

%S 1,2,4,16,56,256,1518,15896,171565,3217779,58858443,1927799742,

%T 63170771231,3671078892600,213376157401433,21677971544137049

%N Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with no more than 7 ones in any 5 X 5 X 5 subtriangle.

%K nonn

%O 0,2

%A _R. H. Hardin_ Jan 03 2009