257754

Appears in sequences

• T(2n+5,n), array T as in A055794.at n=15A055798
• Triangle, read by rows, T(n, k) = binomial(3*n, 2*k) + binomial(3*n, 2*(n-k)).at n=31A154919
• Triangle, read by rows, T(n, k) = binomial(3*n, 2*k) + binomial(3*n, 2*(n-k)).at n=32A154919
• a(n) = 2*(2*n+1)*A000538(n) - 4*A000330(n)^2.at n=9A259317
• a(n) = (1/(n+1)) * Sum_{k=0..n} k^3 * (k+1) * binomial(2*n-k,n-k).at n=9A390966