11320066

Appears in sequences

• Number of paths from (0,0) to (3n,0) that stay in the first quadrant, consist of steps u=(2,1), U=(1,2), or d=(1,-1) and do not touch the x-axis, except at the endpoints.at n=8A108424
• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and have k returns to the x-axis.at n=36A108435
• G.f. satisfies A(x) = 1 + x/A(x)*(1 + 1/A(x)).at n=9A364394