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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 35 |
| 5 | 116 |
| 6 | 606 |
| 7 | 2990 |
| 8 | 11203 |
| 9 | 65368 |
| 10 | 567558 |
| 11 | 3229942 |
| 12 | 12730946 |
| 13 | 78628616 |
| 14 | 666394746 |
| 15 | 3968286590 |
| 16 | 21143707843 |
| 17 | 160244432497 |
| 18 | 1602468019110 |
| 19 | 20852615681805 |
| 20 | 320475672814590 |
| 21 | 4102188681702086 |
| 22 | 36438823274699332 |
[1,3,10,35,116,606,2990,11203,65368,567558, 3229942,12730946,78628616,666394746,3968286590, 21143707843,160244432497,1602468019110, 20852615681805,320475672814590,4102188681702086, 36438823274699332] |