122656domain: NAppears in sequencesNumber of vertices formed when n equally spaced points are placed around a circle and all pairs of points are joined by an interior arc whose radius equals the circle's radius.at n=38A371254Expansion of g^2/(1 - x^3*g^2), where g = 1+x*g^3 is the g.f. of A001764.at n=8A391124