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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 45 |
| 5 | 152 |
| 6 | 535 |
| 7 | 1943 |
| 8 | 7289 |
| 9 | 27876 |
| 10 | 108448 |
| 11 | 428477 |
| 12 | 1716434 |
| 13 | 6947541 |
| 14 | 28393225 |
| 15 | 117079643 |
| 16 | 486515806 |
| 17 | 2034989189 |
| 18 | 8565051207 |
| 19 | 36256323523 |
| 20 | 154246683731 |
| 21 | 659219337990 |
| 22 | 2829613175204 |
| 23 | 12193980235432 |
| 24 | 52737388566862 |
| 25 | 228850945637483 |
| 26 | 996246088634899 |
| 27 | 4349589171641900 |
[1,2,5,14,45,152,535,1943,7289,27876,108448, 428477,1716434,6947541,28393225,117079643, 486515806,2034989189,8565051207,36256323523, 154246683731,659219337990,2829613175204, 12193980235432,52737388566862,228850945637483, 996246088634899,4349589171641900] |