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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 12 |
| 3 | 25 |
| 4 | 440 |
| 5 | 2907 |
| 6 | 7100 |
| 7 | 134821 |
| 8 | 934004 |
| 9 | 2277108 |
| 10 | 46296108 |
| 11 | 330908530 |
| 12 | 820702285 |
| 13 | 17258404593 |
| 14 | 125752465794 |
| 15 | 315014793177 |
| 16 | 6765057712760 |
| 17 | 49918706666467 |
| 18 | 125910537922412 |
| 19 | 2743415189299833 |
| 20 | 20425391744058298 |
[3,12,25,440,2907,7100,134821,934004,2277108, 46296108,330908530,820702285,17258404593, 125752465794,315014793177,6765057712760, 49918706666467,125910537922412,2743415189299833, 20425391744058298] |