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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 23 |
| 4 | 79 |
| 5 | 272 |
| 6 | 943 |
| 7 | 3278 |
| 8 | 11419 |
| 9 | 39830 |
| 10 | 139057 |
| 11 | 485795 |
| 12 | 1697905 |
| 13 | 5936348 |
| 14 | 20760271 |
| 15 | 72615143 |
| 16 | 254028355 |
| 17 | 888758030 |
| 18 | 3109714117 |
| 19 | 10881403229 |
| 20 | 38077702909 |
| 21 | 133251869648 |
| 22 | 466325356273 |
| 23 | 1631981113112 |
| 24 | 5711490384901 |
[1,2,7,23,79,272,943,3278,11419,39830,139057, 485795,1697905,5936348,20760271,72615143, 254028355,888758030,3109714117,10881403229, 38077702909,133251869648,466325356273, 1631981113112,5711490384901] |