Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 8 ones in any 4 X 4 X 4 subtriangle.
A153961
Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 8 ones in any 4 X 4 X 4 subtriangle.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =4a(4) =6a(5) =14a(6) =27a(7) =80a(8) =210a(9) =805a(10) =2370a(11) =12127a(12) =45783a(13) =276334a(14) =1343098a(15) =10464249a(16) =60421447a(17) =607880695a(18) =4555562667a(19) =54131941863a(20) =525633914241
External references
- oeis: A153961