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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 124 |
| 5 | 2396 |
| 6 | 64856 |
| 7 | 2452472 |
| 8 | 124483360 |
| 9 | 8146185504 |
| 10 | 668645524032 |
| 11 | 67374446014272 |
| 12 | 8183368905811584 |
| 13 | 1179807474740449920 |
| 14 | 199266648878034317568 |
| 15 | 38984601149045449948416 |
| 16 | 8748103140554862876727296 |
| 17 | 2232274640259371687436982272 |
| 18 | 642805438643602793466093711360 |
[1,1,2,10,124,2396,64856,2452472,124483360, 8146185504,668645524032,67374446014272, 8183368905811584,1179807474740449920, 199266648878034317568,38984601149045449948416, 8748103140554862876727296, 2232274640259371687436982272, 642805438643602793466093711360] |