4242920400

Appears in sequences

• Number of tree-rooted bridgeless planar maps with two vertices and n faces.at n=17A002740
• Number of sequences {s(i): i=0..n} such that |s(i)-s(i-1)|=1, i=1..n and s(i)=0 at four values of i, one of which is i=0.at n=34A052207