Computer Programming Contest Preparation

    1 Between 1 and 20, 18 generates the longest sequence of 20 values.
    2 Between 35 and 55, 54 generates the longest sequence of 112 values.
    3 Between 25 and 155, 129 generates the longest sequence of 121 values.
    4 Between 25 and 155, 129 generates the longest sequence of 121 values.
    5 Between 75 and 150, 129 generates the longest sequence of 121 values.
    6 Between 250 and 350, 327 generates the longest sequence of 143 values.
    7 Between 450 and 451, 450 generates the longest sequence of 53 values.
    8 Between 500 and 10000, 6171 generates the longest sequence of 261 values.