1381905

Appears in sequences

• a(n) = (n-1)!! - (n-2)!!.at n=13A007911
• Triangle read by rows: d(n,k) = number of decreasing labeled trees with n nodes and largest leaf <= k, for 1 <= k <= n.at n=42A079268
• Difference between the double factorial of the n-th nonnegative odd number and the double factorial of the n-th nonnegative even number.at n=7A122649