411740

Appears in sequences

• Triangle, read by rows, where the n-th row lists the (n^2+1) coefficients of (1+2*x+...+(n+1)*x^n)^n.at n=54A329709
• a(n) = Sum_{k=0..floor(n/3)} binomial(n,k) * binomial(2*k,n-3*k).at n=17A389125