50280

Appears in sequences

• E.g.f. A(x) satisfies: A(A(x)) = x*A'(x) with A(0)=0, A'(0)=1.at n=6A179420
• a(n) = Sum_{k=0..n} k*A000009(k).at n=30A270105
• Place n equally spaced points on each side of an equilateral triangle, and join each of these points by a chord to the 2*n new points on the other two sides: sequence gives number of edges in the resulting planar graph.at n=11A366485