221680

Appears in sequences

• Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (0, 1), (1, -1)}.at n=18A151375
• Row 3 of array in A211400.at n=6A255489
• Number of (undirected) Hamiltonian cycles of the graph of the n-th Johnson solid.at n=40A343211