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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 31 |
| 5 | 105 |
| 6 | 343 |
| 7 | 1198 |
| 8 | 4056 |
| 9 | 14506 |
| 10 | 50350 |
| 11 | 183284 |
| 12 | 647809 |
| 13 | 2390121 |
| 14 | 8564543 |
| 15 | 31933830 |
| 16 | 115664164 |
| 17 | 434920398 |
| 18 | 1588917802 |
| 19 | 6016012236 |
| 20 | 22134533070 |
| 21 | 84289034154 |
| 22 | 311957090678 |
| 23 | 1193717733900 |
| 24 | 4440128821376 |
| 25 | 17060985356980 |
| 26 | 63732279047612 |
| 27 | 245768668712296 |
| 28 | 921501110779045 |
[0,1,3,10,31,105,343,1198,4056,14506,50350,183284, 647809,2390121,8564543,31933830,115664164, 434920398,1588917802,6016012236,22134533070, 84289034154,311957090678,1193717733900, 4440128821376,17060985356980,63732279047612, 245768668712296,921501110779045] |