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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 120 |
| 3 | 371 |
| 4 | 2080 |
| 5 | 11282 |
| 6 | 60568 |
| 7 | 334906 |
| 8 | 1852576 |
| 9 | 10208628 |
| 10 | 56476986 |
| 11 | 312311660 |
| 12 | 1726835768 |
| 13 | 9548532077 |
| 14 | 52807525484 |
| 15 | 292024665946 |
| 16 | 1614879713366 |
| 17 | 8930532980138 |
| 18 | 49386528451002 |
| 19 | 273109909878597 |
| 20 | 1510322716604761 |
[3,120,371,2080,11282,60568,334906,1852576, 10208628,56476986,312311660,1726835768,9548532077, 52807525484,292024665946,1614879713366, 8930532980138,49386528451002,273109909878597, 1510322716604761] |