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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 10 |
| 3 | 37 |
| 4 | 135 |
| 5 | 493 |
| 6 | 1800 |
| 7 | 6572 |
| 8 | 23996 |
| 9 | 87614 |
| 10 | 319895 |
| 11 | 1167997 |
| 12 | 4264577 |
| 13 | 15570774 |
| 14 | 56851829 |
| 15 | 207576737 |
| 16 | 757901769 |
| 17 | 2767242128 |
| 18 | 10103722287 |
| 19 | 36890593353 |
| 20 | 134694505577 |
| 21 | 491795012865 |
| 22 | 1795636233585 |
| 23 | 6556206140806 |
| 24 | 23937943641806 |
| 25 | 87401941533192 |
[1,3,10,37,135,493,1800,6572,23996,87614,319895, 1167997,4264577,15570774,56851829,207576737, 757901769,2767242128,10103722287,36890593353, 134694505577,491795012865,1795636233585, 6556206140806,23937943641806,87401941533192] |