34248

Appears in sequences

• a(n) = T(2n,n-1), T given by A026648.at n=7A026650
• a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026648.at n=7A026972
• Triangle read by rows: T(n,k) is the number of 2-compositions of n having k even entries in the top row. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.at n=58A181336
• A boustrophedon triangle.at n=51A227862
• Riordan array (1/(1-3*x), (1-3*x-sqrt(1-6*x+5*x^2))/(2*x)).at n=37A236420
• Number of Dyck paths of semilength n such that the number of peaks is strongly decreasing from lower to higher levels.at n=15A288141
• Number of nonagons that can be formed with perimeter n.at n=48A288255