base: 2
  one level: [2, 6]
    2 = (1 0)_{2}
    6 = (1 1 0)_{2}
base: 3
  one level: [7, 16, 25]
    7 = (2 1)_{3}
    16 = (1 2 1)_{3}
    25 = (2 2 1)_{3}
base: 5
  one level: [23, 48, 73, 98, 123]
    23 = (4 3)_{5}
    48 = (1 4 3)_{5}
    73 = (2 4 3)_{5}
    98 = (3 4 3)_{5}
    123 = (4 4 3)_{5}
