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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 11 |
| 5 | 81 |
| 6 | 351 |
| 7 | 1149 |
| 8 | 3529 |
| 9 | 12601 |
| 10 | 52724 |
| 11 | 222641 |
| 12 | 879308 |
| 13 | 3295384 |
| 14 | 12303201 |
| 15 | 47320365 |
| 16 | 186738507 |
| 17 | 739129809 |
| 18 | 2894481813 |
| 19 | 11237844615 |
| 20 | 43647142533 |
| 21 | 170543919327 |
| 22 | 669744238998 |
| 23 | 2633027605209 |
| 24 | 10337488816041 |
| 25 | 40544676533466 |
[0,1,1,1,11,81,351,1149,3529,12601,52724,222641, 879308,3295384,12303201,47320365,186738507, 739129809,2894481813,11237844615,43647142533, 170543919327,669744238998,2633027605209, 10337488816041,40544676533466] |