Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 5 ones in any 3 X 3 X 3 subtriangle.
A153940
Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 5 ones in any 3 X 3 X 3 subtriangle.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =3a(4) =7a(5) =12a(6) =23a(7) =97a(8) =172a(9) =639a(10) =2729a(11) =9135a(12) =35231a(13) =283089a(14) =990826a(15) =7193827a(16) =60573511a(17) =397978987a(18) =3029188158a(19) =47855760575a(20) =329376229908
External references
- oeis: A153940