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| n | a(n) |
|---|---|
| 1 | 128 |
| 2 | 410 |
| 3 | 840 |
| 4 | 4004 |
| 5 | 8648 |
| 6 | 52784 |
| 7 | 114056 |
| 8 | 790712 |
| 9 | 1693448 |
| 10 | 12487208 |
| 11 | 26563080 |
| 12 | 201742280 |
| 13 | 427484168 |
| 14 | 3292956296 |
| 15 | 6963468296 |
| 16 | 54006743816 |
| 17 | 114088980488 |
| 18 | 887752094216 |
| 19 | 1874426109960 |
| 20 | 14608478297096 |
| 21 | 30837161410568 |
[128,410,840,4004,8648,52784,114056,790712, 1693448,12487208,26563080,201742280,427484168, 3292956296,6963468296,54006743816,114088980488, 887752094216,1874426109960,14608478297096, 30837161410568] |