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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 44 |
| 5 | 238 |
| 6 | 1363 |
| 7 | 8129 |
| 8 | 49947 |
| 9 | 313982 |
| 10 | 2009804 |
| 11 | 13054923 |
| 12 | 85835763 |
| 13 | 570162938 |
| 14 | 3820449453 |
| 15 | 25792692527 |
| 16 | 175277931388 |
| 17 | 1198017908942 |
| 18 | 8230391249548 |
| 19 | 56801549666858 |
| 20 | 393622890736512 |
| 21 | 2737841490099777 |
| 22 | 19107124975145342 |
| 23 | 133755761621788177 |
| 24 | 938960164858527807 |
| 25 | 6608463199584560132 |
| 26 | 46621379983243723382 |
| 27 | 329627663780846842009 |
[1,1,2,9,44,238,1363,8129,49947,313982,2009804, 13054923,85835763,570162938,3820449453, 25792692527,175277931388,1198017908942, 8230391249548,56801549666858,393622890736512, 2737841490099777,19107124975145342, 133755761621788177,938960164858527807, 6608463199584560132,46621379983243723382, 329627663780846842009] |