255680170

Appears in sequences

• Number of paths from (0,0) to (3n,0) that stay in first quadrant (but may touch horizontal axis) and where each step is (2,1), (1,2) or (1,-1).at n=10A027307
• Length of list created by n substitutions k -> Range[-abs(k+1), abs(k-1), 2] starting with {0}.at n=19A084078
• Number of paths from (0,0) if n is even, or from (2,1) if n is odd, to (3n,0) that stay in first quadrant (but may touch horizontal axis) and where each step is (2,1), (1,2) or (1,-1).at n=20A137842