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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 3 |
| 6 | 5 |
| 7 | 11 |
| 8 | 28 |
| 9 | 87 |
| 10 | 331 |
| 11 | 1565 |
| 12 | 9440 |
| 13 | 72908 |
| 14 | 712687 |
| 15 | 8940809 |
| 16 | 146775560 |
| 17 | 3135694178 |
| 18 | 86745468962 |
| 19 | 3153522201617 |
| 20 | 151857397825012 |
| 21 | 9589042822673342 |
| 22 | 797159462260375958 |
| 23 | 88429042471401581924 |
| 24 | 13020775433175768654191 |
| 25 | 2532864078831923248348591 |
[1,1,1,1,2,3,5,11,28,87,331,1565,9440,72908, 712687,8940809,146775560,3135694178,86745468962, 3153522201617,151857397825012,9589042822673342, 797159462260375958,88429042471401581924, 13020775433175768654191,2532864078831923248348591] |