1.
| 2.
| 3.
| 4.
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6.
| 7.
| 8.
| 9.
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10.
| 11.
| 12.
| 13.
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14.
| 15.
| 16.
| 17.
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18.
| 19.
| 20.
| 21.
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The solutions are here.
Put a number in each block so that each number not in the bottom row is the sum of exactly 2 blocks it touches (vertically or diagonally) below it.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
The solutions are here.