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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 23 |
| 2 | 275 |
| 3 | 2277 |
| 4 | 14673 |
| 5 | 78407 |
| 6 | 361514 |
| 7 | 1477750 |
| 8 | 5461235 |
| 9 | 18518565 |
| 10 | 58282576 |
| 11 | 171815888 |
| 12 | 477989151 |
| 13 | 1262643305 |
| 14 | 3183445871 |
| 15 | 7694405993 |
| 16 | 17895700206 |
| 17 | 40182143330 |
| 18 | 87349858045 |
| 19 | 184297593435 |
| 20 | 378236260170 |
| 21 | 756560791350 |
[1,23,275,2277,14673,78407,361514,1477750,5461235, 18518565,58282576,171815888,477989151,1262643305, 3183445871,7694405993,17895700206,40182143330, 87349858045,184297593435,378236260170, 756560791350] |