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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 45 |
| 5 | 198 |
| 6 | 919 |
| 7 | 4445 |
| 8 | 22215 |
| 9 | 114000 |
| 10 | 597790 |
| 11 | 3191070 |
| 12 | 17289023 |
| 13 | 94845796 |
| 14 | 525838005 |
| 15 | 2941748627 |
| 16 | 16585870501 |
| 17 | 94147448172 |
| 18 | 537592229784 |
| 19 | 3085816136840 |
| 20 | 17795391949590 |
| 21 | 103051160368120 |
| 22 | 598997937352830 |
| 23 | 3493575551891610 |
| 24 | 20438727738501275 |
| 25 | 119911429466179978 |
[1,1,3,11,45,198,919,4445,22215,114000,597790, 3191070,17289023,94845796,525838005,2941748627, 16585870501,94147448172,537592229784, 3085816136840,17795391949590,103051160368120, 598997937352830,3493575551891610, 20438727738501275,119911429466179978] |