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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 13 |
| 5 | 39 |
| 6 | 120 |
| 7 | 393 |
| 8 | 1327 |
| 9 | 4621 |
| 10 | 16507 |
| 11 | 60136 |
| 12 | 223256 |
| 13 | 841162 |
| 14 | 3213799 |
| 15 | 12423749 |
| 16 | 48544749 |
| 17 | 191494444 |
| 18 | 761889311 |
| 19 | 3054986938 |
| 20 | 12336481332 |
| 21 | 50140341202 |
| 22 | 205001854887 |
| 23 | 842763707626 |
| 24 | 3482160659347 |
| 25 | 14455350510899 |
| 26 | 60270145567922 |
| 27 | 252314239272496 |
| 28 | 1060308335923336 |
| 29 | 4471663866791576 |
[1,1,2,5,13,39,120,393,1327,4621,16507,60136, 223256,841162,3213799,12423749,48544749,191494444, 761889311,3054986938,12336481332,50140341202, 205001854887,842763707626,3482160659347, 14455350510899,60270145567922,252314239272496, 1060308335923336,4471663866791576] |