3 9 7 3 13 5 45
Permutations: 1658475   Chunk size:     414618  Chunks: 4
$VAR1 = [
          [
            [
              1,
              '1'
            ],
            [
              414618,
              '6 5 0 9 3 33'
            ]
          ],
          [
            [
              414619,
              '6 5 0 9 3 34'
            ],
            [
              829236,
              '1 4 3 1 6 2 21'
            ]
          ],
          [
            [
              829237,
              '1 4 3 1 6 2 22'
            ],
            [
              1243854,
              '2 2 1 2 3 1 9'
            ]
          ],
          [
            [
              1243855,
              '2 2 1 2 3 1 10'
            ],
            [
              1658475,
              '2 8 6 2 12 4 44'
            ]
          ]
        ];