“…We add here also the case (1, 3) as an equilateral triangle with mass m 0 = 0 located at its center of gravity ( [3,10,12]). An interesting configuration of the type ( p, N ) can be (2,8), where eight point-masses are situated at the vertices of an equilateral triangle and a pentagon, which are concentric, (see, for example [13]). In our paper we deal with a special class of central configurations of the type (2, 3n), consisting of 3n bodies located at the vertices of two regular concentric polygons: the "interior" one of the radius q and with n equal point-masses, and other 2n bodies located at the vertices of the second regular 2n-gon of the radius, say, q , with point-masses of two categories: one half, i.e., n masses, all equal to, say m 2 , and another half, i.e.…”