9150655216

Appears in sequences

• Number of walks on square lattice that start and end at origin after 2n steps, not touching origin at intermediate stages.at n=10A054474
• Triangular array read by rows. T(n,k) is the number of square lattice walks that start and end at the origin after 2n steps having k primitive loops; n>=1, 1<=k<=n.at n=45A227997