Number of 2n-celled free polyominoes with 1 hole that have the 180-degree rotation symmetry and no others.
A057425
Number of 2n-celled free polyominoes with 1 hole that have the 180-degree rotation symmetry and no others.
Terms
- a(0) =1a(1) =7a(2) =42a(3) =193a(4) =853a(5) =3553a(6) =14564a(7) =58636a(8) =234523a(9) =931938
External references
- oeis: A057425