880660

Appears in sequences

• a(n) = Sum_{k=0..n} binomial(n*(n-k), k).at n=9A099237
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,k) = [x^n] 1/(1 - x*(1+x)^n)^k.at n=64A362079