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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 17 |
| 4 | 75 |
| 5 | 289 |
| 6 | 1319 |
| 7 | 5599 |
| 8 | 26119 |
| 9 | 115565 |
| 10 | 546181 |
| 11 | 2479009 |
| 12 | 11826313 |
| 13 | 54632367 |
| 14 | 262421783 |
| 15 | 1227762805 |
| 16 | 5927841717 |
| 17 | 27999421111 |
| 18 | 135725203143 |
| 19 | 645839470791 |
| 20 | 3140610933561 |
| 21 | 15032660778051 |
| 22 | 73290799948377 |
| 23 | 352492126056567 |
| 24 | 1722254570888947 |
| 25 | 8315990976797781 |
| 26 | 40705284451722057 |
| 27 | 197199319886308395 |
[1,1,5,17,75,289,1319,5599,26119,115565,546181, 2479009,11826313,54632367,262421783,1227762805, 5927841717,27999421111,135725203143,645839470791, 3140610933561,15032660778051,73290799948377, 352492126056567,1722254570888947,8315990976797781, 40705284451722057,197199319886308395] |