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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 8 |
| 4 | 47 |
| 5 | 224 |
| 6 | 1130 |
| 7 | 4868 |
| 8 | 23404 |
| 9 | 97230 |
| 10 | 457264 |
| 11 | 1868456 |
| 12 | 8679894 |
| 13 | 35162196 |
| 14 | 162087345 |
| 15 | 653396608 |
| 16 | 2996092939 |
| 17 | 12041970574 |
| 18 | 55006554003 |
| 19 | 220673343660 |
| 20 | 1005105011265 |
| 21 | 4027407386110 |
| 22 | 18302390130349 |
| 23 | 73278803406040 |
| 24 | 332412585527847 |
| 25 | 1330205838019114 |
| 26 | 6025308727310905 |
[1,8,47,224,1130,4868,23404,97230,457264,1868456, 8679894,35162196,162087345,653396608,2996092939, 12041970574,55006554003,220673343660, 1005105011265,4027407386110,18302390130349, 73278803406040,332412585527847,1330205838019114, 6025308727310905] |