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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 36 |
| 5 | 180 |
| 6 | 941 |
| 7 | 5079 |
| 8 | 27961 |
| 9 | 156129 |
| 10 | 880883 |
| 11 | 5009625 |
| 12 | 28668920 |
| 13 | 164897622 |
| 14 | 952418882 |
| 15 | 5520254925 |
| 16 | 32090787577 |
| 17 | 187030223470 |
| 18 | 1092467751427 |
| 19 | 6393706661582 |
| 20 | 37484034980109 |
| 21 | 220093799592140 |
| 22 | 1294100839792723 |
| 23 | 7618482099893824 |
| 24 | 44901233075819275 |
[0,1,2,8,36,180,941,5079,27961,156129,880883, 5009625,28668920,164897622,952418882,5520254925, 32090787577,187030223470,1092467751427, 6393706661582,37484034980109,220093799592140, 1294100839792723,7618482099893824, 44901233075819275] |