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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 22 |
| 6 | 66 |
| 7 | 212 |
| 8 | 715 |
| 9 | 2438 |
| 10 | 8398 |
| 11 | 29372 |
| 12 | 104006 |
| 13 | 371516 |
| 14 | 1337220 |
| 15 | 4847208 |
| 16 | 17678835 |
| 17 | 64823110 |
| 18 | 238819350 |
| 19 | 883629164 |
| 20 | 3282060210 |
| 21 | 12233141908 |
| 22 | 45741281820 |
| 23 | 171529777432 |
| 24 | 644952073662 |
| 25 | 2430973304732 |
| 26 | 9183676536076 |
[1,1,2,7,22,66,212,715,2438,8398,29372,104006, 371516,1337220,4847208,17678835,64823110, 238819350,883629164,3282060210,12233141908, 45741281820,171529777432,644952073662, 2430973304732,9183676536076] |