138531

Appears in sequences

• Base 9 digits are, in order, the first n terms of the periodic sequence with initial period 2,3,1,0.at n=5A037756
• a(n) is the total number of down steps between the second and third up steps in all 2_1-Dyck paths of length 3*n. A 2_1-Dyck path is a lattice path with steps (1, 2), (1, -1) that starts and ends at y = 0 and stays above the line y = -1.at n=8A334643