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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 11 |
| 4 | 34 |
| 5 | 96 |
| 6 | 288 |
| 7 | 833 |
| 8 | 2456 |
| 9 | 7175 |
| 10 | 21054 |
| 11 | 61633 |
| 12 | 180674 |
| 13 | 529220 |
| 14 | 1550800 |
| 15 | 4543446 |
| 16 | 13312552 |
| 17 | 39004278 |
| 18 | 114281748 |
| 19 | 334837511 |
| 20 | 981059294 |
| 21 | 2874447292 |
| 22 | 8421986238 |
| 23 | 24675963950 |
| 24 | 72299290794 |
| 25 | 211833080161 |
| 26 | 620659794584 |
| 27 | 1818500391218 |
| 28 | 5328110328116 |
| 29 | 15611082044176 |
| 30 | 45739647180588 |
| 31 | 134014753120706 |
| 32 | 392656158141832 |
[1,1,4,11,34,96,288,833,2456,7175,21054,61633, 180674,529220,1550800,4543446,13312552,39004278, 114281748,334837511,981059294,2874447292, 8421986238,24675963950,72299290794,211833080161, 620659794584,1818500391218,5328110328116, 15611082044176,45739647180588,134014753120706, 392656158141832] |