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| n | a(n) |
|---|---|
| 1 | 332 |
| 2 | 1200 |
| 3 | 4312 |
| 4 | 15572 |
| 5 | 56276 |
| 6 | 203768 |
| 7 | 738516 |
| 8 | 2680636 |
| 9 | 9738960 |
| 10 | 35432228 |
| 11 | 129023908 |
| 12 | 470470536 |
| 13 | 1717000260 |
| 14 | 6274522924 |
| 15 | 22948524144 |
| 16 | 84039182132 |
| 17 | 308005315508 |
| 18 | 1130228790408 |
| 19 | 4150565943156 |
| 20 | 15260094453244 |
| 21 | 56146361267440 |
[332,1200,4312,15572,56276,203768,738516,2680636, 9738960,35432228,129023908,470470536,1717000260, 6274522924,22948524144,84039182132,308005315508, 1130228790408,4150565943156,15260094453244, 56146361267440] |