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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 38 |
| 4 | 329 |
| 5 | 2614 |
| 6 | 17400 |
| 7 | 122843 |
| 8 | 901647 |
| 9 | 6662758 |
| 10 | 48492622 |
| 11 | 351153718 |
| 12 | 2549170764 |
| 13 | 18557754476 |
| 14 | 135119522565 |
| 15 | 982657665633 |
| 16 | 7145326366447 |
| 17 | 51965861513279 |
| 18 | 377997475235382 |
| 19 | 2749505470031020 |
| 20 | 19998020429893220 |
| 21 | 145451451407796951 |
| 22 | 1057925773226867974 |
[1,1,5,38,329,2614,17400,122843,901647,6662758, 48492622,351153718,2549170764,18557754476, 135119522565,982657665633,7145326366447, 51965861513279,377997475235382,2749505470031020, 19998020429893220,145451451407796951, 1057925773226867974] |