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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 5 |
| 3 | 10 |
| 4 | 13 |
| 5 | 24 |
| 6 | 39 |
| 7 | 84 |
| 8 | 168 |
| 9 | 370 |
| 10 | 836 |
| 11 | 1998 |
| 12 | 4622 |
| 13 | 11284 |
| 14 | 28151 |
| 15 | 53565 |
| 16 | 138230 |
| 17 | 334125 |
| 18 | 659741 |
| 19 | 1716635 |
| 20 | 3977282 |
| 21 | 10430384 |
| 22 | 27132843 |
| 23 | 71588934 |
| 24 | 189472352 |
| 25 | 505341104 |
| 26 | 1353331592 |
[4,5,10,13,24,39,84,168,370,836,1998,4622,11284, 28151,53565,138230,334125,659741,1716635,3977282, 10430384,27132843,71588934,189472352,505341104, 1353331592] |