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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 43 |
| 5 | 181 |
| 6 | 797 |
| 7 | 3625 |
| 8 | 16903 |
| 9 | 80367 |
| 10 | 388157 |
| 11 | 1899093 |
| 12 | 9392501 |
| 13 | 46881963 |
| 14 | 235863891 |
| 15 | 1194811579 |
| 16 | 6089105493 |
| 17 | 31197589525 |
| 18 | 160601295503 |
| 19 | 830278627047 |
| 20 | 4308870293511 |
| 21 | 22439404479929 |
| 22 | 117228234264769 |
| 23 | 614197712145461 |
[1,1,3,11,43,181,797,3625,16903,80367,388157, 1899093,9392501,46881963,235863891,1194811579, 6089105493,31197589525,160601295503,830278627047, 4308870293511,22439404479929,117228234264769, 614197712145461] |