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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 17 |
| 3 | 31 |
| 4 | 135 |
| 5 | 547 |
| 6 | 1938 |
| 7 | 6965 |
| 8 | 25953 |
| 9 | 95602 |
| 10 | 350544 |
| 11 | 1288829 |
| 12 | 4742540 |
| 13 | 17436564 |
| 14 | 64107857 |
| 15 | 235741082 |
| 16 | 866860297 |
| 17 | 3187480223 |
| 18 | 11720639783 |
| 19 | 43098018497 |
| 20 | 158475393298 |
| 21 | 582728318557 |
| 22 | 2142746395133 |
| 23 | 7879078188002 |
| 24 | 28972099906592 |
[4,17,31,135,547,1938,6965,25953,95602,350544, 1288829,4742540,17436564,64107857,235741082, 866860297,3187480223,11720639783,43098018497, 158475393298,582728318557,2142746395133, 7879078188002,28972099906592] |