Number of polygons of length 2n with one hole on square lattice (not allowing rotations).

A056634

Number of polygons of length 2n with one hole on square lattice (not allowing rotations).

Terms

    a(0) =1a(1) =24a(2) =342a(3) =3804a(4) =36802a(5) =326540a(6) =2735308a(7) =22006264a(8) =171912401a(9) =1313614776a(10) =9868281330a(11) =73150450248a(12) =536495354621

External references