Number of fixed polyominoes with n cells that have fourfold rotational symmetry centered at the center of a cell.
A348849
Number of fixed polyominoes with n cells that have fourfold rotational symmetry centered at the center of a cell.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =0a(6) =0a(7) =1a(8) =2a(9) =0a(10) =0a(11) =3a(12) =6a(13) =0a(14) =0a(15) =10a(16) =18a(17) =0a(18) =0a(19) =35a(20) =57a(21) =0a(22) =0a(23) =126a(24) =191a(25) =0a(26) =0a(27) =461a(28) =658a(29) =0
External references
- oeis: A348849