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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 14 |
| 3 | 49 |
| 4 | 250 |
| 5 | 1183 |
| 6 | 5918 |
| 7 | 28680 |
| 8 | 141255 |
| 9 | 691968 |
| 10 | 3391358 |
| 11 | 16627204 |
| 12 | 81517689 |
| 13 | 399591042 |
| 14 | 1958997017 |
| 15 | 9603668921 |
| 16 | 47080079771 |
| 17 | 230803211309 |
| 18 | 1131476255863 |
| 19 | 5546875012244 |
| 20 | 27192677194545 |
| 21 | 133307748424215 |
| 22 | 653519804327678 |
[1,14,49,250,1183,5918,28680,141255,691968, 3391358,16627204,81517689,399591042,1958997017, 9603668921,47080079771,230803211309,1131476255863, 5546875012244,27192677194545,133307748424215, 653519804327678] |