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| n | a(n) |
|---|---|
| 1 | 48 |
| 2 | 330 |
| 3 | 1836 |
| 4 | 8280 |
| 5 | 32740 |
| 6 | 120728 |
| 7 | 427390 |
| 8 | 1483442 |
| 9 | 5092432 |
| 10 | 17465996 |
| 11 | 59892736 |
| 12 | 206614336 |
| 13 | 715176178 |
| 14 | 2495327868 |
| 15 | 8742073364 |
| 16 | 30872946806 |
| 17 | 109440726728 |
| 18 | 390821924176 |
| 19 | 1400125471630 |
| 20 | 5048928185428 |
| 21 | 18254562891404 |
| 22 | 66379155129368 |
[48,330,1836,8280,32740,120728,427390,1483442, 5092432,17465996,59892736,206614336,715176178, 2495327868,8742073364,30872946806,109440726728, 390821924176,1400125471630,5048928185428, 18254562891404,66379155129368] |