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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 48 |
| 3 | 328 |
| 4 | 3216 |
| 5 | 18940 |
| 6 | 102958 |
| 7 | 437416 |
| 8 | 1745476 |
| 9 | 6074164 |
| 10 | 19546414 |
| 11 | 57274236 |
| 12 | 158706286 |
| 13 | 408770608 |
| 14 | 1005752468 |
| 15 | 2347176012 |
| 16 | 5262852883 |
| 17 | 11312035800 |
| 18 | 23548549548 |
| 19 | 47322841540 |
| 20 | 92544936670 |
| 21 | 175876801036 |
| 22 | 326378292388 |
[2,48,328,3216,18940,102958,437416,1745476, 6074164,19546414,57274236,158706286,408770608, 1005752468,2347176012,5262852883,11312035800, 23548549548,47322841540,92544936670,175876801036, 326378292388] |