343200

Appears in sequences

• Triangle T(n, k) = coefficients of (p(x,n)), where p(x, n) = (n-1)! * Sum_{j=1..n} A142458(n, j)*binomial(x+j-1, n-1), read by rows.at n=24A168295
• Expansion of 30*x*(1 + x) / (1 - x)^4.at n=31A316459
• a(n) = ( binomial(7*n,2*n)*binomial(7*n/2,2*n)*binomial(2*n,n)^2 ) / binomial(7*n/2,n)^2.at n=3A352652
• a(n) is the number of ways the labels 1 to 2^n-1 can be assigned to a perfect binary tree with n levels such that there is an ordering between children and parents and also an ordering between the left and the right child.at n=3A363197