Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 9 ones in any 5 X 5 X 5 subtriangle.
A153970
Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 9 ones in any 5 X 5 X 5 subtriangle.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =4a(4) =7a(5) =12a(6) =22a(7) =77a(8) =142a(9) =532a(10) =1881a(11) =6680a(12) =23965a(13) =163600a(14) =576849a(15) =3866824a(16) =26635009a(17) =176366633a(18) =1204710337a(19) =15393505413a(20) =104674234457
External references
- oeis: A153970