Number of deco polyominoes of height n in which all columns end at an even level. A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.

A121751

Number of deco polyominoes of height n in which all columns end at an even level. 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) =2a(3) =4a(4) =14a(5) =44a(6) =194a(7) =812a(8) =4362a(9) =22716a(10) =144282a(11) =897636a(12) =6587454a(13) =47632188a(14) =396765018a(15) =3268365228a(16) =30471767658a(17) =281641273164

External references