Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 7 ones in any 4 X 4 X 4 subtriangle.
A153955
Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 7 ones in any 4 X 4 X 4 subtriangle.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =4a(4) =6a(5) =13a(6) =23a(7) =76a(8) =165a(9) =617a(10) =1952a(11) =8422a(12) =29972a(13) =193873a(14) =777019a(15) =5693242a(16) =34246559a(17) =286416710a(18) =1965573794a(19) =24471858943a(20) =192131736735
External references
- oeis: A153955