357238

Appears in sequences

• a(n) = 2*Catalan(n) - Catalan(n-1).at n=11A000782
• Number of unrooted triangulations with reflection symmetry of a disk with one internal node and n+3 nodes on the boundary.at n=22A005508
• a(n) = (7*n+2)*C(n)/(n+2), where C(n) is the n-th Catalan number.at n=10A061557
• Triangle read by rows: T(n,k) is the number of Dyck n-paths containing k even-length descents to ground level.at n=50A111301
• If p and q are (odd) twin primes and q > p then p*q^2+(p+q)+1 is divisible by 3; a(n) = (p*q^2+(p+q)+1)/3.at n=8A164689