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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 13 |
| 4 | 40 |
| 5 | 117 |
| 6 | 348 |
| 7 | 1029 |
| 8 | 3049 |
| 9 | 9028 |
| 10 | 26738 |
| 11 | 79183 |
| 12 | 234502 |
| 13 | 694476 |
| 14 | 2056692 |
| 15 | 6090891 |
| 16 | 18038173 |
| 17 | 53420041 |
| 18 | 158203433 |
| 19 | 468519406 |
| 20 | 1387520047 |
| 21 | 4109140098 |
| 22 | 12169216863 |
| 23 | 36039131181 |
| 24 | 106729873498 |
| 25 | 316080480394 |
| 26 | 936072224321 |
[1,1,5,13,40,117,348,1029,3049,9028,26738,79183, 234502,694476,2056692,6090891,18038173,53420041, 158203433,468519406,1387520047,4109140098, 12169216863,36039131181,106729873498,316080480394, 936072224321] |