Free polyominoes with 4n squares, having 90-degree rotational symmetry about a square corner, but not having reflective symmetry.
A234007
Free polyominoes with 4n squares, having 90-degree rotational symmetry about a square corner, but not having reflective symmetry.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =9a(4) =30a(5) =110a(6) =387a(7) =1419a(8) =5185a(9) =19225a(10) =71634a(11) =269250a(12) =1017260a(13) =3864267a(14) =14742260a(15) =56470053a(16) =217052829a(17) =836878982
External references
- oeis: A234007