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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 10 |
| 6 | 29 |
| 7 | 72 |
| 8 | 230 |
| 9 | 700 |
| 10 | 2421 |
| 11 | 8308 |
| 12 | 30070 |
| 13 | 108990 |
| 14 | 403188 |
| 15 | 1497057 |
| 16 | 5607200 |
| 17 | 21076570 |
| 18 | 79595257 |
| 19 | 301492044 |
| 20 | 1145558141 |
| 21 | 4363503609 |
| 22 | 16660196142 |
| 23 | 63741248200 |
| 24 | 244339616370 |
| 25 | 938255682540 |
| 26 | 3608668279965 |
| 27 | 13900021843855 |
| 28 | 53614339995060 |
| 29 | 207062143625710 |
[1,1,1,2,5,10,29,72,230,700,2421,8308,30070, 108990,403188,1497057,5607200,21076570,79595257, 301492044,1145558141,4363503609,16660196142, 63741248200,244339616370,938255682540, 3608668279965,13900021843855,53614339995060, 207062143625710] |