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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 2 |
| 5 | 2 |
| 6 | 5 |
| 7 | 18 |
| 8 | 20 |
| 9 | 34 |
| 10 | 148 |
| 11 | 243 |
| 12 | 673 |
| 13 | 1248 |
| 14 | 3321 |
| 15 | 6864 |
| 16 | 17337 |
| 17 | 39632 |
| 18 | 99576 |
| 19 | 243766 |
| 20 | 630498 |
| 21 | 1574713 |
| 22 | 4196482 |
| 23 | 10768129 |
| 24 | 28840282 |
| 25 | 75641476 |
| 26 | 202359008 |
| 27 | 535092286 |
| 28 | 1428265543 |
| 29 | 3778608704 |
| 30 | 10050453841 |
[0,2,2,5,18,20,34,148,243,673,1248,3321,6864, 17337,39632,99576,243766,630498,1574713,4196482, 10768129,28840282,75641476,202359008,535092286, 1428265543,3778608704,10050453841] |