145945800

Appears in sequences

• Number of cycles with entries of the same parity in all fixed-point-free involutions of {1,2,...,2n}.at n=9A161122
• A Galton triangle: T(n,k) = 2*k*T(n-1,k) + (2*k-1)*T(n-1,k-1).at n=43A187075