1926638

Appears in sequences

• a(n) = Sum_{i=1..floor((n+1)/4)} a(2*i-1) * a(n-2*i+1), with a(1)=a(2)=1 and a(3)=7.at n=18A024733
• Number of bipartite outerplanar graphs on n unlabeled nodes.at n=15A111759