Number of 2-cell columns starting at level 0 in all of 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.
A121636
Number of 2-cell columns starting at level 0 in all of 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) =5a(3) =23a(4) =122a(5) =754a(6) =5364a(7) =43308a(8) =391824a(9) =3929616a(10) =43287840a(11) =519711840a(12) =6755460480a(13) =94527008640
External references
- oeis: A121636