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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 22 |
| 4 | 85 |
| 5 | 340 |
| 6 | 1411 |
| 7 | 6036 |
| 8 | 26163 |
| 9 | 114983 |
| 10 | 513060 |
| 11 | 2308456 |
| 12 | 10465788 |
| 13 | 47829991 |
| 14 | 219922058 |
| 15 | 1016135334 |
| 16 | 4717666738 |
| 17 | 21999886908 |
| 18 | 102949227180 |
| 19 | 483335249790 |
| 20 | 2276438144176 |
| 21 | 10750317622193 |
| 22 | 50890349439787 |
| 23 | 241472604286962 |
| 24 | 1148196982158353 |
| 25 | 5469920809676455 |
| 26 | 26105092657585897 |
| 27 | 124796430590276424 |
[1,2,6,22,85,340,1411,6036,26163,114983,513060, 2308456,10465788,47829991,219922058,1016135334, 4717666738,21999886908,102949227180,483335249790, 2276438144176,10750317622193,50890349439787, 241472604286962,1148196982158353,5469920809676455, 26105092657585897,124796430590276424] |