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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 54 |
| 6 | 190 |
| 7 | 684 |
| 8 | 2505 |
| 9 | 9291 |
| 10 | 34793 |
| 11 | 131277 |
| 12 | 498312 |
| 13 | 1900862 |
| 14 | 7280732 |
| 15 | 27983141 |
| 16 | 107868939 |
| 17 | 416869874 |
| 18 | 1614609446 |
| 19 | 6265869591 |
| 20 | 24358231651 |
| 21 | 94837442844 |
| 22 | 369755864507 |
| 23 | 1443420649734 |
| 24 | 5641088964709 |
| 25 | 22068939198169 |
[1,2,5,16,54,190,684,2505,9291,34793,131277, 498312,1900862,7280732,27983141,107868939, 416869874,1614609446,6265869591,24358231651, 94837442844,369755864507,1443420649734, 5641088964709,22068939198169] |