Number of even-length first columns in all deco polyominoes of height n. A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.
A121696
Number of even-length first columns in all deco polyominoes of height n. A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.
Terms
- a(0) =0a(1) =1a(2) =3a(3) =9a(4) =63a(5) =297a(6) =2583a(7) =17577a(8) =184023a(9) =1630377a(10) =20142423a(11) =219358377a(12) =3133652823a(13) =40455492777a(14) =656970836823
External references
- oeis: A121696