Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 12 ones in any 5 X 5 X 5 subtriangle.

A153999

Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 12 ones in any 5 X 5 X 5 subtriangle.

Terms

    a(0) =1a(1) =2a(2) =2a(3) =4a(4) =8a(5) =15a(6) =30a(7) =113a(8) =226a(9) =897a(10) =3372a(11) =13821a(12) =54535a(13) =410690a(14) =1677109a(15) =13057708a(16) =99242206a(17) =798041029a(18) =6266181287a(19) =94041421473a(20) =762970233334

External references