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| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 113 |
| 3 | 241 |
| 4 | 1442 |
| 5 | 7580 |
| 6 | 45897 |
| 7 | 320405 |
| 8 | 2489823 |
| 9 | 20679119 |
| 10 | 181479109 |
| 11 | 1638029668 |
| 12 | 15055216000 |
| 13 | 140041815820 |
| 14 | 1311377207833 |
| 15 | 12333793776935 |
| 16 | 116324158971711 |
| 17 | 1098943034315150 |
| 18 | 10393405509745294 |
| 19 | 98366682504010661 |
| 20 | 931394618765660697 |
[13,113,241,1442,7580,45897,320405,2489823, 20679119,181479109,1638029668,15055216000, 140041815820,1311377207833,12333793776935, 116324158971711,1098943034315150, 10393405509745294,98366682504010661, 931394618765660697] |