1.
| 2.
| 3.
| 4.
| 5.
|
6.
| 7.
| 8.
| 9.
|
10.
| 11.
| 12.
| 13.
|
14.
| 15.
| 16.
|
The solutions are here.
Starting with the circle containing 1, successively jump 1, 2, and 3 units in a horizontal or vertical direction to place the next number. Each circle should contain a number, and no numbers should be placed outside circles. The first puzzle is solved as an example.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
The solutions are here.