110901

Appears in sequences

• Number of 3-element proper antichains of an n-element set.at n=7A051303
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, -1, 1), (-1, 0, -1), (1, -1, -1), (1, 1, 1)}.at n=10A149501