Three hexagons and the twenty-eight first strictly positive integer numbers -nine of them being prime numbers- [Trois hexagones et les vingt-huit premiers nombres entiers strictement positifs -neuf d'entre-eux étant des nombres premiers-].

                    V = 3x3 + 3 + 1 = 13 different vertices (9 single vertices, 3 double vertices and 1 triple vertice)

                    S = 3x4 + 3 = 15 different sides (12 single sides and 3 double sides).

• The P=9 first prime numbers {2,3,5,7,11,13,17,19,23}, recalling that 1 is not a prime number, are on "special" vertices (white figures), when the N-P=28-9=19 remaining integer numbers are on the remaining vertices as well as on the middle of each side (grey figures). Then each of the N integer numbers is used once and only once.


• All the sums of the three different numbers contained on each side (two on the vertices and one on the middle) must be equal to a certain value (a priori unknown):

                      
                       1 + 15 + 28 = 44
                       1 + 16 + 27 = 44
                       1 + 21 + 22 = 44
                       2 + 14 + 28 = 44
                       2 + 17 + 25 = 44
                       3 + 18 + 23 = 44
                       3 + 20 + 21 = 44
                       4 + 19 + 21 = 44
                       5 + 12 + 27 = 44
                       5 + 13 + 26 = 44
                       6 + 11 + 27 = 44
                       7 +  9 + 28 = 44
                       7 + 13 + 24 = 44
                       8 + 17 + 19 = 44
                      10 + 11 + 23 = 44