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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 22 |
| 4 | 101 |
| 5 | 476 |
| 6 | 2282 |
| 7 | 11075 |
| 8 | 54245 |
| 9 | 267592 |
| 10 | 1327580 |
| 11 | 6617128 |
| 12 | 33110090 |
| 13 | 166215895 |
| 14 | 836761343 |
| 15 | 4222640822 |
| 16 | 21354409445 |
| 17 | 108193910000 |
| 18 | 549084400088 |
| 19 | 2790744368660 |
| 20 | 14203023709276 |
| 21 | 72371208424880 |
| 22 | 369170645788840 |
| 23 | 1885051297844624 |
[1,1,5,22,101,476,2282,11075,54245,267592,1327580, 6617128,33110090,166215895,836761343,4222640822, 21354409445,108193910000,549084400088, 2790744368660,14203023709276,72371208424880, 369170645788840,1885051297844624] |