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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 13 |
| 4 | 55 |
| 5 | 183 |
| 6 | 819 |
| 7 | 2879 |
| 8 | 13133 |
| 9 | 49151 |
| 10 | 225573 |
| 11 | 872295 |
| 12 | 4045205 |
| 13 | 16029755 |
| 14 | 74663695 |
| 15 | 301759043 |
| 16 | 1412144445 |
| 17 | 5789266935 |
| 18 | 27186913513 |
| 19 | 112832278421 |
| 20 | 531322739697 |
| 21 | 2226905904509 |
| 22 | 10512271065583 |
| 23 | 44429462141699 |
| 24 | 210144837585317 |
| 25 | 894555768002507 |
| 26 | 4238535802222079 |
| 27 | 18154480397519071 |
[1,1,5,13,55,183,819,2879,13133,49151,225573, 872295,4045205,16029755,74663695,301759043, 1412144445,5789266935,27186913513,112832278421, 531322739697,2226905904509,10512271065583, 44429462141699,210144837585317,894555768002507, 4238535802222079,18154480397519071] |