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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 26 |
| 6 | 75 |
| 7 | 218 |
| 8 | 640 |
| 9 | 1898 |
| 10 | 5682 |
| 11 | 17155 |
| 12 | 52187 |
| 13 | 159827 |
| 14 | 492417 |
| 15 | 1525222 |
| 16 | 4746906 |
| 17 | 14837444 |
| 18 | 46558573 |
| 19 | 146614539 |
| 20 | 463186317 |
| 21 | 1467631144 |
| 22 | 4662899110 |
| 23 | 14851847390 |
| 24 | 47414162252 |
| 25 | 151692982789 |
| 26 | 486280700344 |
| 27 | 1561757802585 |
| 28 | 5024492606869 |
| 29 | 16191028967145 |
| 30 | 52253656263073 |
| 31 | 168880350860512 |
[1,3,9,26,75,218,640,1898,5682,17155,52187,159827, 492417,1525222,4746906,14837444,46558573, 146614539,463186317,1467631144,4662899110, 14851847390,47414162252,151692982789,486280700344, 1561757802585,5024492606869,16191028967145, 52253656263073,168880350860512] |