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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 39 |
| 4 | 131 |
| 5 | 421 |
| 6 | 1309 |
| 7 | 3971 |
| 8 | 11823 |
| 9 | 34691 |
| 10 | 100611 |
| 11 | 289033 |
| 12 | 823801 |
| 13 | 2332419 |
| 14 | 6566291 |
| 15 | 18394911 |
| 16 | 51310979 |
| 17 | 142587181 |
| 18 | 394905493 |
| 19 | 1090444931 |
| 20 | 3002921271 |
| 21 | 8249479163 |
| 22 | 22612505091 |
| 23 | 61857842449 |
| 24 | 168903452401 |
| 25 | 460409998851 |
[1,3,11,39,131,421,1309,3971,11823,34691,100611, 289033,823801,2332419,6566291,18394911,51310979, 142587181,394905493,1090444931,3002921271, 8249479163,22612505091,61857842449,168903452401, 460409998851] |