486200

Appears in sequences

• a(n) = n*binomial(2*n-2, n-1).at n=10A037965
• a(n) = C(n)*(11n+1) where C(n) = Catalan numbers (A000108).at n=9A050490
• Expansion of (1+9*x)/(1-x)^11.at n=9A056114
• Number of ways to fill an n X n matrix with numbers 1, 2, ..., n*n such that each row and each column is decreasing or increasing.at n=3A062528
• Triangle read by rows: T(n,k) = binomial(n,k)*binomial(2*n-2*k,n-1), n>=1, 0<=k<=floor(n/2+1/2).at n=35A138767
• Irregular triangle, read by rows, T(n, k) = binomial(2*n, k)*binomial(2*k, k).at n=34A156789
• Row sums of the extended Catalan triangle A189231.at n=18A189911
• Triangle T(n,m) read by rows: the sum of runs of all sequences arranging n objects of one type and m objects of another type.at n=54A349147