12271350

Appears in sequences

• 10th column of Catalan triangle A009766.at n=13A124088
• a(n) = (n-1)*binomial(3*n-2,n)/(2*n-1) + (n+1)*binomial(3*n,n)/(2*n+1) - binomial(3*n-1,n).at n=11A262717
• Number of North-East lattice paths from (0,0) to (n,n) that cross the diagonal y = x horizontally exactly three times.at n=9A268446