Each row is a cycle [?] of 483 726 159. And even the cycles have a pattern: 665 665 66. That is, you can rotate the first row by 6 to get the second row, then

Each row is a cycle [?] of 483 726 159. And even the cycles have a pattern: 665 665 66. That is, you can rotate the first row by 6 to get the second row, then rotate again by 6, then by 5, etc. The columns are almost as consistent, but not quite.