901995588

Appears in sequences

• Number of walks on square lattice. Column y=2 of A052174.at n=16A005560
• a(n) is the number of walks from (0,0) to (0,2) that remain in the upper half-plane y >= 0 using 2*n unit steps either up (U), down (D), left (L) or right (R).at n=8A145601