287028

Appears in sequences

• a(n) = 31*binomial(2*n,n-4) + Sum_{i=1..n-4} binomial(2*n,n-4-i)*(4+i).at n=9A182025
• a(n) = Sum_{k=0..n} Sum_{m=0..floor(k/2)} binomial(k-m, m)*binomial(n-k, k-m)^2.at n=14A306463