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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 12 |
| 3 | 63 |
| 4 | 405 |
| 5 | 3024 |
| 6 | 25515 |
| 7 | 239355 |
| 8 | 2465478 |
| 9 | 27600669 |
| 10 | 333051669 |
| 11 | 4303119330 |
| 12 | 59202612693 |
| 13 | 863285928327 |
| 14 | 13288589222508 |
| 15 | 215177742933579 |
| 16 | 3654114236490393 |
| 17 | 64902307993517160 |
| 18 | 1202782377224829015 |
| 19 | 23207417212751493327 |
| 20 | 465302639045308247262 |
| 21 | 9677171073270491712513 |
| 22 | 208434297638273958963225 |
[1,3,12,63,405,3024,25515,239355,2465478,27600669, 333051669,4303119330,59202612693,863285928327, 13288589222508,215177742933579,3654114236490393, 64902307993517160,1202782377224829015, 23207417212751493327,465302639045308247262, 9677171073270491712513,208434297638273958963225] |