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

A057410

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

Terms

    a(0) =1a(1) =12a(2) =94a(3) =604a(4) =3463a(5) =18440a(6) =93274a(7) =454412a(8) =2151673a(9) =9964500a(10) =45335002a(11) =203303760a(12) =900901387a(13) =3952468348a(14) =17194102478a(15) =74257185512a(16) =318693463933

External references