214326000

Appears in sequences

• Triangle read by rows: number of nilpotent partial transformations (of an n-element set) of height r (height(alpha) = |Im(alpha)|), 0 <= r < n.at n=49A141618
• Number of (n+2)X(2+2) 0..1 arrays with nondecreasing sum of every three consecutive values in every row and column.at n=11A251188
• a(n) = Stirling2(2*n, n)*(2*n)!/(n+1)!.at n=5A390727