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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 2 |
| 7 | 5 |
| 8 | 18 |
| 9 | 61 |
| 10 | 229 |
| 11 | 879 |
| 12 | 3588 |
| 13 | 15283 |
| 14 | 68029 |
| 15 | 314985 |
| 16 | 1512982 |
| 17 | 7523664 |
| 18 | 38653397 |
| 19 | 204844184 |
| 20 | 1118152388 |
| 21 | 6278617770 |
| 22 | 36225373016 |
| 23 | 214531854676 |
| 24 | 1302820719810 |
| 25 | 8106006393514 |
| 26 | 51629965051190 |
| 27 | 336384879743751 |
| 28 | 2240263173545424 |
| 29 | 15240406795991028 |
| 30 | 105840760976497158 |
| 31 | 749907226527126570 |
[1,1,1,1,1,1,2,5,18,61,229,879,3588,15283,68029, 314985,1512982,7523664,38653397,204844184, 1118152388,6278617770,36225373016,214531854676, 1302820719810,8106006393514,51629965051190, 336384879743751,2240263173545424, 15240406795991028,105840760976497158, 749907226527126570] |