8115660

Appears in sequences

• Number of labeled n-node 4-valent graphs containing 3 double edges, a distinguished unordered pair of which are adjacent.at n=9A058833
• a(0)=1; for n>0, p2(n)+Sum(binomial(2*k,k)*p2(n-k)/2,k=1..n-1) where p2 = A002995, the number of unlabeled planar trees on n nodes.at n=14A191280