1312740

Appears in sequences

• a(n) = (2n+4)!/(4!*n!*(n+1)!).at n=7A002803
• Triangle read by rows: T(n,k) = binomial(2*n,2*k)*binomial(2*n-2*k,n-k)/(n+1-k) for 0<=k<=n.at n=47A280580