3640210

Appears in sequences

• Number of positive clusters of type D_n.at n=12A129869
• Sum of root degrees of all symmetric ordered trees with n edges.at n=22A143360
• Stepped path in P(k,n) array of k-th partial sums of squares (A000290).at n=21A259775
• Square array read by ascending antidiagonals: T(n,k) = [x^k] (1 - x)^(2*k) * Legendre_P(n*k-1, (1 + x)/(1 - x)) for n, k >= 0.at n=40A364513
• a(n) = (1/2) * (6*n)!*(2*n)!^2/((3*n)!*(4*n)!*n!^3) for n >= 1 with a(0) = 1.at n=4A364515
• a(n) = (1/(n+1)) * Sum_{k=0..n} k^2 * (k+1) * binomial(2*n-k,n-k).at n=12A390965