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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 17 |
| 3 | 73 |
| 4 | 273 |
| 5 | 881 |
| 6 | 3785 |
| 7 | 13081 |
| 8 | 48737 |
| 9 | 184321 |
| 10 | 632193 |
| 11 | 2526305 |
| 12 | 8854081 |
| 13 | 32077921 |
| 14 | 124093025 |
| 15 | 428178641 |
| 16 | 1638563969 |
| 17 | 5878561921 |
| 18 | 21469361537 |
| 19 | 82252171393 |
| 20 | 286863949025 |
| 21 | 1061000856417 |
| 22 | 3998983314849 |
| 23 | 14361380710817 |
[1,5,17,73,273,881,3785,13081,48737,184321,632193, 2526305,8854081,32077921,124093025,428178641, 1638563969,5878561921,21469361537,82252171393, 286863949025,1061000856417,3998983314849, 14361380710817] |