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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 30 |
| 2 | 198 |
| 3 | 1026 |
| 4 | 6238 |
| 5 | 38350 |
| 6 | 241614 |
| 7 | 1541878 |
| 8 | 9944222 |
| 9 | 64647846 |
| 10 | 422988918 |
| 11 | 2782157694 |
| 12 | 18379498222 |
| 13 | 121868659046 |
| 14 | 810638482054 |
| 15 | 5406986392966 |
| 16 | 36151528042142 |
| 17 | 242224492645286 |
| 18 | 1626022574433846 |
| 19 | 10933656445976458 |
[1,30,198,1026,6238,38350,241614,1541878,9944222, 64647846,422988918,2782157694,18379498222, 121868659046,810638482054,5406986392966, 36151528042142,242224492645286,1626022574433846, 10933656445976458] |