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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 16 |
| 4 | 43 |
| 5 | 109 |
| 6 | 266 |
| 7 | 639 |
| 8 | 1529 |
| 9 | 3674 |
| 10 | 8909 |
| 11 | 21853 |
| 12 | 54252 |
| 13 | 136213 |
| 14 | 345373 |
| 15 | 882828 |
| 16 | 2271143 |
| 17 | 5871373 |
| 18 | 15234214 |
| 19 | 39633091 |
| 20 | 103306417 |
| 21 | 269641062 |
| 22 | 704462713 |
| 23 | 1841692605 |
| 24 | 4816973880 |
| 25 | 12602801545 |
[1,6,16,43,109,266,639,1529,3674,8909,21853,54252, 136213,345373,882828,2271143,5871373,15234214, 39633091,103306417,269641062,704462713,1841692605, 4816973880,12602801545] |