751236

Appears in sequences

• Number of restricted hexagonal polyominoes with n cells.at n=11A002212
• Number of polyhexes with n hexagons, having reflectional symmetry (see Harary and Read for precise definition).at n=21A002215
• a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-2)*a(2) for n >= 3.at n=11A025238
• Path-counting array T; each step of a path is (1 right) or (1 up) to a point below line y=x, else (1 right and 1 up) or (1 up) to a point on the line y=x, else (1 left) or (1 up) to a point above line y=x. T(i,j)=number of paths to point (i-j,j), for 1<=j<=i, i >= 1.at n=65A055450