44152809

Appears in sequences

• Central trinomial coefficients: largest coefficient of (1 + x + x^2)^n.at n=18A002426
• Number of symmetric, reduced unit interval schemes with n+1 intervals (n>=1).at n=36A005213
• Sum of the squares of the trinomial coefficients (A027907).at n=9A082758
• Number of 9*n X n 0..2 arrays with row sums 2 and column sums 18.at n=1A172718
• a(n) = Sum_{k=0..n} C(n,k)*((-1)^n*(C(k,n-k)-C(k,n-k-1))+C(n-k,k+1)).at n=18A273020