10059033600
domain: N
Appears in sequences
- a(n) = (2*n)!*(2*n+1)! / n!^2.at n=5A000909
- a(n) = binomial(n,floor(n/2))*(n+1)!.at n=10A002867
- Number of descents beginning and ending with an odd number in all permutations of {1,2,...,n}.at n=12A152885
- Number of descents beginning with an even number and ending with an odd number in all permutations of {1,2,...,n}.at n=12A152887
- Triangle read by rows: binomial(n,k)*(2*n-k)!, n>=0, 0<=k<=n.at n=30A328826