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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 9 |
| 3 | 44 |
| 4 | 446 |
| 5 | 3334 |
| 6 | 27540 |
| 7 | 219070 |
| 8 | 1766136 |
| 9 | 14168766 |
| 10 | 113870162 |
| 11 | 914550470 |
| 12 | 7346946970 |
| 13 | 59015933032 |
| 14 | 474072774244 |
| 15 | 3808166264624 |
| 16 | 30590638905810 |
| 17 | 245731343642532 |
| 18 | 1973934759524284 |
| 19 | 15856413036814582 |
| 20 | 127372929035331130 |
[0,9,44,446,3334,27540,219070,1766136,14168766, 113870162,914550470,7346946970,59015933032, 474072774244,3808166264624,30590638905810, 245731343642532,1973934759524284, 15856413036814582,127372929035331130] |