88230

Appears in sequences

• G.f. A(x) satisfies: A(x) = x*(1 + 4*A(x)*A'(x)) / (1 + A(x)*A'(x)).at n=5A301933
• Expansion of exp(Sum_{k>=1} (-1)^(k+1)*x^k/(k*sqrt(1 - 4*x^k))).at n=10A305256
• The number of edges inside a pentagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.at n=6A329710
• Table read by antidiagonals: Place k equally spaced points on each side of a regular n-gon and join every pair of the n*(k+1) boundary points by a chord; T(n,k) (n >= 3, k >= 0) gives the number of edges in the resulting planar graph.at n=38A367324