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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 5 |
| 5 | 18 |
| 6 | 24 |
| 7 | 84 |
| 8 | 115 |
| 9 | 400 |
| 10 | 554 |
| 11 | 1934 |
| 12 | 2690 |
| 13 | 9474 |
| 14 | 13180 |
| 15 | 46962 |
| 16 | 65193 |
| 17 | 235338 |
| 18 | 325568 |
| 19 | 1191292 |
| 20 | 1641192 |
| 21 | 6086880 |
| 22 | 8348342 |
| 23 | 31369180 |
| 24 | 42831204 |
| 25 | 162943236 |
| 26 | 221515918 |
| 27 | 852512496 |
| 28 | 1154208486 |
| 29 | 4489722568 |
| 30 | 6055426942 |
[1,1,4,5,18,24,84,115,400,554,1934,2690,9474, 13180,46962,65193,235338,325568,1191292,1641192, 6086880,8348342,31369180,42831204,162943236, 221515918,852512496,1154208486,4489722568, 6055426942] |