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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 37 |
| 4 | 215 |
| 5 | 1271 |
| 6 | 7651 |
| 7 | 46614 |
| 8 | 286599 |
| 9 | 1774630 |
| 10 | 11050897 |
| 11 | 69134572 |
| 12 | 434174819 |
| 13 | 2735565574 |
| 14 | 17283825370 |
| 15 | 109466361512 |
| 16 | 694764983463 |
| 17 | 4417771590123 |
| 18 | 28137563496298 |
| 19 | 179478199605550 |
| 20 | 1146342590242465 |
| 21 | 7330598365285470 |
| 22 | 46928753892901140 |
[1,1,7,37,215,1271,7651,46614,286599,1774630, 11050897,69134572,434174819,2735565574, 17283825370,109466361512,694764983463, 4417771590123,28137563496298,179478199605550, 1146342590242465,7330598365285470, 46928753892901140] |