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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 33 |
| 4 | 153 |
| 5 | 644 |
| 6 | 3079 |
| 7 | 13796 |
| 8 | 66951 |
| 9 | 309900 |
| 10 | 1516751 |
| 11 | 7163139 |
| 12 | 35252495 |
| 13 | 168702164 |
| 14 | 833311863 |
| 15 | 4024832013 |
| 16 | 19933067217 |
| 17 | 96923446796 |
| 18 | 480935723503 |
| 19 | 2350317848041 |
| 20 | 11679152784131 |
| 21 | 57296876389616 |
| 22 | 285034184537707 |
| 23 | 1402601392007074 |
| 24 | 6983561015163199 |
| 25 | 34448127705013148 |
| 26 | 171635610631292203 |
[1,2,9,33,153,644,3079,13796,66951,309900,1516751, 7163139,35252495,168702164,833311863,4024832013, 19933067217,96923446796,480935723503, 2350317848041,11679152784131,57296876389616, 285034184537707,1402601392007074,6983561015163199, 34448127705013148,171635610631292203] |