449141836

Appears in sequences

• a(n) = (2*n)!*(2*n+1)! / (n! * (n+1)!)^2.at n=9A000891
• a(n) is the number of n-step walks on square lattice such that 0 <= y <= x at each step.at n=18A005558
• Tenth column (and diagonal) of Narayana triangle A001263.at n=9A134291
• Moment sequence of tr(A^2) in USp(4).at n=18A138350
• Number of 9 X 9 matrices with elements in 0..n with each row and each column in nondecreasing order. 9,9,n can be permuted, see formula.at n=2A140924