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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 1 |
| 4 | 8 |
| 5 | 12 |
| 6 | 45 |
| 7 | 98 |
| 8 | 292 |
| 9 | 725 |
| 10 | 2004 |
| 11 | 5210 |
| 12 | 14051 |
| 13 | 37126 |
| 14 | 99336 |
| 15 | 263991 |
| 16 | 704622 |
| 17 | 1876566 |
| 18 | 5005327 |
| 19 | 13341292 |
| 20 | 35579622 |
| 21 | 94866875 |
| 22 | 252998042 |
| 23 | 674677856 |
| 24 | 1799331865 |
| 25 | 4798687520 |
| 26 | 12798199466 |
| 27 | 34133165825 |
| 28 | 91035612400 |
| 29 | 242799614636 |
| 30 | 647572193925 |
| 31 | 1727149489058 |
[1,0,2,1,8,12,45,98,292,725,2004,5210,14051,37126, 99336,263991,704622,1876566,5005327,13341292, 35579622,94866875,252998042,674677856,1799331865, 4798687520,12798199466,34133165825,91035612400, 242799614636,647572193925,1727149489058] |