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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 28 |
| 5 | 77 |
| 6 | 323 |
| 7 | 1027 |
| 8 | 4499 |
| 9 | 15234 |
| 10 | 68652 |
| 11 | 244482 |
| 12 | 1119699 |
| 13 | 4128033 |
| 14 | 19132050 |
| 15 | 72551151 |
| 16 | 339255496 |
| 17 | 1313734573 |
| 18 | 6186905395 |
| 19 | 24392958836 |
| 20 | 115515119719 |
| 21 | 461965418939 |
| 22 | 2197874309312 |
| 23 | 8900519548172 |
| 24 | 42506496184050 |
| 25 | 173921532421315 |
| 26 | 833329355690755 |
| 27 | 3441435610292513 |
| 28 | 16534808770189511 |
[1,1,3,7,28,77,323,1027,4499,15234,68652,244482, 1119699,4128033,19132050,72551151,339255496, 1313734573,6186905395,24392958836,115515119719, 461965418939,2197874309312,8900519548172, 42506496184050,173921532421315,833329355690755, 3441435610292513,16534808770189511] |