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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 132 |
| 3 | 1452 |
| 4 | 15972 |
| 5 | 175692 |
| 6 | 1932612 |
| 7 | 21258732 |
| 8 | 233846052 |
| 9 | 2572306572 |
| 10 | 28295372292 |
| 11 | 311249095146 |
| 12 | 3423740045880 |
| 13 | 37661140496760 |
| 14 | 414272545377240 |
| 15 | 4556997998191320 |
| 16 | 50126977969563000 |
| 17 | 551396757549236280 |
[1,12,132,1452,15972,175692,1932612,21258732, 233846052,2572306572,28295372292,311249095146, 3423740045880,37661140496760,414272545377240, 4556997998191320,50126977969563000, 551396757549236280] |