71021

Appears in sequences

• Triangle read by rows: T(n,k) is the number of directed column-convex polyominoes of area n and having k cells in the shortest column (1<=k<=n).at n=78A121301
• Number of directed column-convex polyominoes having at least one 1-cell column.at n=12A121302
• Number of n X 2 0..1 arrays with each 1 adjacent to 2, 3 or 4 king-move neighboring 1s.at n=9A296821