3006003

Appears in sequences

• Number of walks on square lattice. Column y=4 of A052174.at n=10A005562
• Triangle read by rows: T(n, k) = binomial(2*n+1, n-k)^2*(2*k+1)/(2*n+1).at n=30A067802
• Fifth column of triangle A103371 (without leading zeros).at n=10A134287
• a(n) is the number of walks from (0,0) to (0,4) that remain in the upper half-plane y >= 0 using 2*n +2 unit steps either up (U), down (D), left (L) or right (R).at n=5A145603
• Denominator of 2n/v(n)^2, where v(1) = 0, v(2) = 1, and v(n) = v(n-1)/(n-2) + v(n-2) for n >= 3. (Limit of 2n/v(n)^2 is Pi.)at n=14A239225
• Triangle read by rows. T(n, k) = (n - k + 1) * binomial(n + k + 1, 2*k)^2 / (n + k + 1).at n=50A370233