28973100

Appears in sequences

• a(n) = 3*binomial(2*n, n-1).at n=13A062561
• Sum of root degrees of all symmetric ordered trees with n edges.at n=25A143360
• G.f.: 3F2([1/9, 5/9, 8/9], [1/3, 1], 729 x).at n=3A275455