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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 18 |
| 3 | 60 |
| 4 | 197 |
| 5 | 650 |
| 6 | 2153 |
| 7 | 7140 |
| 8 | 23682 |
| 9 | 78545 |
| 10 | 260498 |
| 11 | 863945 |
| 12 | 2865282 |
| 13 | 9502740 |
| 14 | 31515953 |
| 15 | 104523050 |
| 16 | 346651997 |
| 17 | 1149675660 |
| 18 | 3812913618 |
| 19 | 12645575405 |
| 20 | 41939208002 |
| 21 | 139091904605 |
| 22 | 461300030418 |
| 23 | 1529907284460 |
| 24 | 5073956524397 |
[1,5,18,60,197,650,2153,7140,23682,78545,260498, 863945,2865282,9502740,31515953,104523050, 346651997,1149675660,3812913618,12645575405, 41939208002,139091904605,461300030418, 1529907284460,5073956524397] |