bjr
nombres premiers inférieurs à 32
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31
31 - 1 = 30 (6 x 5)
29 - 1 = 28 non
23 - 1 = 22 non
19 - 1 = 18 (6 x 3)
17 - 1 = 16 non
13 - 1 = 12 (6 x 2)
11 - 1 = 10 non
7 - 1 = 6 (6 x 1)
terminé
il y a 4 réponses
31 ; 19 ; 13 et 7
