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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 32 |
| 5 | 107 |
| 6 | 406 |
| 7 | 1543 |
| 8 | 6090 |
| 9 | 24146 |
| 10 | 98643 |
| 11 | 406416 |
| 12 | 1695798 |
| 13 | 7137445 |
| 14 | 30371510 |
| 15 | 130114585 |
| 16 | 561109001 |
| 17 | 2434945076 |
| 18 | 10628079754 |
| 19 | 46605896147 |
| 20 | 205271832088 |
| 21 | 907951122880 |
| 22 | 4031163410729 |
| 23 | 17957103579357 |
| 24 | 80244610168837 |
| 25 | 359663685481550 |
| 26 | 1616386069956481 |
| 27 | 7282307288193565 |
| 28 | 32886927632112087 |
[1,1,3,9,32,107,406,1543,6090,24146,98643,406416, 1695798,7137445,30371510,130114585,561109001, 2434945076,10628079754,46605896147,205271832088, 907951122880,4031163410729,17957103579357, 80244610168837,359663685481550,1616386069956481, 7282307288193565,32886927632112087] |