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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 9 |
| 3 | 22 |
| 4 | 142 |
| 5 | 1146 |
| 6 | 7456 |
| 7 | 55663 |
| 8 | 400028 |
| 9 | 2906875 |
| 10 | 21162204 |
| 11 | 153677233 |
| 12 | 1117612488 |
| 13 | 8123629685 |
| 14 | 59057261422 |
| 15 | 429317113075 |
| 16 | 3120977422852 |
| 17 | 22688267741133 |
| 18 | 164934718709179 |
| 19 | 1199012026918226 |
| 20 | 8716348960310287 |
| 21 | 63364478025520501 |
[0,9,22,142,1146,7456,55663,400028,2906875, 21162204,153677233,1117612488,8123629685, 59057261422,429317113075,3120977422852, 22688267741133,164934718709179,1199012026918226, 8716348960310287,63364478025520501] |