Number of staircase polygons of area n with any number of (staircase polygon) holes on square lattice (not allowing rotations).

A057417

Number of staircase polygons of area n with any number of (staircase polygon) holes on square lattice (not allowing rotations).

Terms

    a(0) =1a(1) =2a(2) =4a(3) =9a(4) =20a(5) =46a(6) =105a(7) =243a(8) =561a(9) =1303a(10) =3026a(11) =7047a(12) =16419a(13) =38314a(14) =89454a(15) =209056a(16) =488810a(17) =1143686a(18) =2677074a(19) =6269438a(20) =14687799a(21) =34423317a(22) =80702234a(23) =189258382a(24) =443958607a(25) =1041704375a(26) =2444830929a(27) =5739200960a(28) =13475465449

External references