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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 52 |
| 6 | 188 |
| 7 | 673 |
| 8 | 2528 |
| 9 | 9448 |
| 10 | 36232 |
| 11 | 138642 |
| 12 | 538502 |
| 13 | 2089746 |
| 14 | 8183600 |
| 15 | 32039011 |
| 16 | 126154812 |
| 17 | 496759140 |
| 18 | 1963415328 |
| 19 | 7761746678 |
| 20 | 30760767292 |
| 21 | 121938877154 |
| 22 | 484214723920 |
| 23 | 1923302168038 |
| 24 | 7648666905624 |
| 25 | 30425224701788 |
| 26 | 121132809344714 |
| 27 | 482381656899028 |
| 28 | 1922197151700130 |
[1,1,2,5,16,52,188,673,2528,9448,36232,138642, 538502,2089746,8183600,32039011,126154812, 496759140,1963415328,7761746678,30760767292, 121938877154,484214723920,1923302168038, 7648666905624,30425224701788,121132809344714, 482381656899028,1922197151700130] |