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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 10 |
| 3 | 33 |
| 4 | 108 |
| 5 | 354 |
| 6 | 1161 |
| 7 | 3807 |
| 8 | 12483 |
| 9 | 40932 |
| 10 | 134217 |
| 11 | 440100 |
| 12 | 1443096 |
| 13 | 4731939 |
| 14 | 15516117 |
| 15 | 50877639 |
| 16 | 166828734 |
| 17 | 547034553 |
| 18 | 1793736576 |
| 19 | 5881695930 |
| 20 | 19286191449 |
| 21 | 63239784075 |
| 22 | 207364440015 |
| 23 | 679951894392 |
| 24 | 2229575035401 |
| 25 | 7310818426248 |
| 26 | 23972310961920 |
[1,3,10,33,108,354,1161,3807,12483,40932,134217, 440100,1443096,4731939,15516117,50877639, 166828734,547034553,1793736576,5881695930, 19286191449,63239784075,207364440015,679951894392, 2229575035401,7310818426248,23972310961920] |