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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 36 |
| 4 | 118 |
| 5 | 351 |
| 6 | 1082 |
| 7 | 3093 |
| 8 | 8984 |
| 9 | 25164 |
| 10 | 70434 |
| 11 | 191808 |
| 12 | 525559 |
| 13 | 1404672 |
| 14 | 3755506 |
| 15 | 9906111 |
| 16 | 26057062 |
| 17 | 67703310 |
| 18 | 175745506 |
| 19 | 451392114 |
| 20 | 1157272780 |
| 21 | 2944110060 |
| 22 | 7468477985 |
| 23 | 18821686554 |
| 24 | 47337840114 |
| 25 | 118344795738 |
| 26 | 295156919969 |
| 27 | 732694232394 |
| 28 | 1814357671094 |
[1,3,11,36,118,351,1082,3093,8984,25164,70434, 191808,525559,1404672,3755506,9906111,26057062, 67703310,175745506,451392114,1157272780, 2944110060,7468477985,18821686554,47337840114, 118344795738,295156919969,732694232394, 1814357671094] |