digraph collatz {
    size="17x11";
    1;
    2 -> 1; // 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25
    3 -> 10; // 3, 6, 12, 24
    4 -> 2; // 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25
    5 -> 16; // 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 22, 23, 24, 25
    6 -> 3; // 6, 12, 24
    7 -> 22; // 7, 9, 14, 18
    8 -> 4; // 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25
    9 -> 28; // 9, 18
    10 -> 5; // 3, 6, 7, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 22, 23, 24, 25
    11 -> 34; // 7, 9, 11, 14, 18, 19, 22, 25
    12 -> 6; // 12, 24
    13 -> 40; // 7, 9, 11, 13, 14, 17, 18, 19, 22, 25
    14 -> 7; // 9, 14, 18
    15 -> 46; // 15
    16 -> 8; // 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25
    17 -> 52; // 7, 9, 11, 14, 17, 18, 19, 22, 25
    18 -> 9; // 18
    19 -> 58; // 19, 25
    20 -> 10; // 7, 9, 11, 13, 14, 15, 17, 18, 19, 20, 22, 23, 25
    21 -> 64; // 21
    22 -> 11; // 7, 9, 14, 18, 19, 22, 25
    23 -> 70; // 15, 23
    24 -> 12; // 24
    25 -> 76; // 25
    26 -> 13; // 7, 9, 11, 14, 17, 18, 19, 22, 25
    28 -> 14; // 9, 18
    29 -> 88; // 19, 25
    32 -> 16; // 21
    34 -> 17; // 7, 9, 11, 14, 18, 19, 22, 25
    35 -> 106; // 15, 23
    38 -> 19; // 25
    40 -> 20; // 7, 9, 11, 13, 14, 15, 17, 18, 19, 22, 23, 25
    44 -> 22; // 19, 25
    46 -> 23; // 15
    52 -> 26; // 7, 9, 11, 14, 17, 18, 19, 22, 25
    53 -> 160; // 15, 23
    58 -> 29; // 19, 25
    64 -> 32; // 21
    70 -> 35; // 15, 23
    76 -> 38; // 25
    80 -> 40; // 15, 23
    88 -> 44; // 19, 25
    106 -> 53; // 15, 23
    160 -> 80; // 15, 23
    // Path of 2: 2, 1
    // Path of 3: 3, 10, 5, 16, 8, 4, 2, 1
    // Path of 4: 4, 2, 1
    // Path of 5: 5, 16, 8, 4, 2, 1
    // Path of 6: 6, 3, 10, 5, 16, 8, 4, 2, 1
    // Path of 7: 7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 8: 8, 4, 2, 1
    // Path of 9: 9, 28, 14, 7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 10: 10, 5, 16, 8, 4, 2, 1
    // Path of 11: 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 12: 12, 6, 3, 10, 5, 16, 8, 4, 2, 1
    // Path of 13: 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 14: 14, 7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 15: 15, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 16: 16, 8, 4, 2, 1
    // Path of 17: 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 18: 18, 9, 28, 14, 7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 19: 19, 58, 29, 88, 44, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 20: 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 21: 21, 64, 32, 16, 8, 4, 2, 1
    // Path of 22: 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 23: 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2, 1
    // Path of 24: 24, 12, 6, 3, 10, 5, 16, 8, 4, 2, 1
    // Path of 25: 25, 76, 38, 19, 58, 29, 88, 44, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1
}