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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 11 |
| 3 | 66 |
| 4 | 470 |
| 5 | 3997 |
| 6 | 40079 |
| 7 | 466448 |
| 8 | 6208551 |
| 9 | 93297013 |
| 10 | 1565360082 |
| 11 | 29047075343 |
| 12 | 591275224311 |
| 13 | 13110484254998 |
| 14 | 314726620750589 |
| 15 | 8135993235767295 |
| 16 | 225426087495479680 |
| 17 | 6666553071325468948 |
| 18 | 209645759506867904384 |
| 19 | 6987310422457948266944 |
| 20 | 246075579251657940919613 |
[1,2,11,66,470,3997,40079,466448,6208551,93297013, 1565360082,29047075343,591275224311, 13110484254998,314726620750589,8135993235767295, 225426087495479680,6666553071325468948, 209645759506867904384,6987310422457948266944, 246075579251657940919613] |