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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 45 |
| 6 | 145 |
| 7 | 479 |
| 8 | 1673 |
| 9 | 5928 |
| 10 | 21602 |
| 11 | 79826 |
| 12 | 300161 |
| 13 | 1144599 |
| 14 | 4414282 |
| 15 | 17226535 |
| 16 | 67793778 |
| 17 | 269250387 |
| 18 | 1077231445 |
| 19 | 4339818022 |
| 20 | 17600218203 |
| 21 | 71764342984 |
| 22 | 294309638092 |
| 23 | 1212500814029 |
| 24 | 5019282722556 |
| 25 | 20864139620821 |
| 26 | 87068515194275 |
| 27 | 364733443455242 |
| 28 | 1532912464126412 |
| 29 | 6464562544654232 |
[1,1,2,5,15,45,145,479,1673,5928,21602,79826, 300161,1144599,4414282,17226535,67793778, 269250387,1077231445,4339818022,17600218203, 71764342984,294309638092,1212500814029, 5019282722556,20864139620821,87068515194275, 364733443455242,1532912464126412,6464562544654232] |