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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 110 |
| 5 | 1330 |
| 6 | 19852 |
| 7 | 351792 |
| 8 | 7209036 |
| 9 | 167607066 |
| 10 | 4357308098 |
| 11 | 125219900520 |
| 12 | 3941126688798 |
| 13 | 134808743674176 |
| 14 | 4979127855477336 |
| 15 | 197480359402576304 |
| 16 | 8370550907396970684 |
| 17 | 377599345119560766534 |
| 18 | 18061714498169627460982 |
[1,2,12,110,1330,19852,351792,7209036,167607066, 4357308098,125219900520,3941126688798, 134808743674176,4979127855477336, 197480359402576304,8370550907396970684, 377599345119560766534,18061714498169627460982] |