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| n | a(n) |
|---|---|
| 1 | 312 |
| 2 | 1996 |
| 3 | 12880 |
| 4 | 88572 |
| 5 | 609912 |
| 6 | 4361260 |
| 7 | 30999664 |
| 8 | 226112364 |
| 9 | 1632434488 |
| 10 | 12023904092 |
| 11 | 87476145488 |
| 12 | 647317646108 |
| 13 | 4727495091576 |
| 14 | 35056982203980 |
| 15 | 256540627260976 |
| 16 | 1904048129719436 |
| 17 | 13948922790405176 |
| 18 | 103557690225690108 |
[312,1996,12880,88572,609912,4361260,30999664, 226112364,1632434488,12023904092,87476145488, 647317646108,4727495091576,35056982203980, 256540627260976,1904048129719436, 13948922790405176,103557690225690108] |