The digits 1-9 each appear four times in the grid, and no two squares which are adjacent horizontally or vertically contain the same digit. Every instance of a digit's occurring more than once in a row or column is mentioned in the clues.
ROWS
1. A pair of 8s enclosing a 5; total is 30
2. A pair of 1s; all the numbers are odd
3. A pair of 4s with 7 the highest number; total is 26
4. A pair of 6s; total is 41
5. A pair of 1s enclosing a 5; total is 23
6. A pair of 2s; total is 34
COLUMNS
1. A pair of 9s; total is 43
2. A pair of 3s with 8 the highest number; total is 28
3. A pair of 7s; all other numbers are even
4. A pair of 5s and a pair of 1s, total is 22
5. A pair of 9s but no 4s; total is 36
6. A pair of 1s but no 5s; total is 17