226512

Appears in sequences

• a(n) = (2*n)!*(2*n+1)! / (n! * (n+1)!)^2.at n=6A000891
• a(n) is the number of n-step walks on square lattice such that 0 <= y <= x at each step.at n=12A005558
• Triangle read by rows: T(n, k) = binomial(2*n+1, n-k)^2*(2*k+1)/(2*n+1).at n=21A067802
• A014486-encodings of trivalent plane trees (tpt) represented as (embedded into) a subset of general plane trees.at n=11A083936
• Square array T(n,k) read by antidiagonals: number of tilings of an <n,k,n> hexagon.at n=30A103905
• Triangle of central coefficients of generalized Pascal-Narayana triangles.at n=38A120258
• Column 6 of triangle A123610.at n=7A123616
• a(n) = binomial(n+7,7)*binomial(n+7,6)/(n+7).at n=6A134288
• Moment sequence of tr(A^2) in USp(4).at n=12A138350
• Number of 6 X 6 matrices with elements in 0..n with each row and each column in nondecreasing order. 6,6,n can be permuted, see formula.at n=2A140906
• Triangle T(n,m) read by rows: T(n,m) = Product_{i=0..5} binomial(n+i,m)/binomial(m+i,m).at n=38A142465
• Triangle T(n,m) read by rows: T(n,m) = Product_{i=0..5} binomial(n+i,m)/binomial(m+i,m).at n=42A142465
• Triangle T(n, k) = binomial(2*n, 2*k)*binomial(2*n+1, 2*k+1)/(2*n-2*k+1), read by rows.at n=24A155516
• Array A(n, k) = (1/2)*(2*n+1)!!*(2*k+1)!!*Integral_{x=-1..1} (1-x^(n+1))*(1-x^(k+1))/(1-x)^2 dx, read by antidiagonals.at n=21A157050
• Array A(n, k) = (1/2)*(2*n+1)!!*(2*k+1)!!*Integral_{x=-1..1} (1-x^(n+1))*(1-x^(k+1))/(1-x)^2 dx, read by antidiagonals.at n=27A157050
• Number of n X 5 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=10A208139
• Number of undirected circular permutations i_1,...,i_{n-1} of 1,...,n-1 with i_1-i_2, ..., i_{n-2}-i_{n-1}, i_{n-1}-i_1 pairwise distinct modulo n.at n=12A228762
• Numbers whose set of decimal digits coincides with the set of the indices of their prime factors.at n=7A318298
• List of e-perfect numbers that are not e-unitary perfect.at n=3A322858
• Array read by ascending antidiagonals: A(n, k) = (n + 1)*binomial(2*k + n - 1, k - 1)^2 / (2*k + n - 1) for k > 0, and A(n, 0) = 0.at n=35A378062