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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 36 |
| 5 | 181 |
| 6 | 1086 |
| 7 | 7607 |
| 8 | 60862 |
| 9 | 547759 |
| 10 | 5477598 |
| 11 | 60253580 |
| 12 | 723042962 |
| 13 | 9399558518 |
| 14 | 131593819259 |
| 15 | 1973907288891 |
| 16 | 31582516622266 |
| 17 | 536902782578529 |
| 18 | 9664250086413531 |
| 19 | 183620751641857104 |
| 20 | 3672415032837142098 |
[1,3,9,36,181,1086,7607,60862,547759,5477598, 60253580,723042962,9399558518,131593819259, 1973907288891,31582516622266,536902782578529, 9664250086413531,183620751641857104, 3672415032837142098] |