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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 10 |
| 2 | 80 |
| 3 | 570 |
| 4 | 3790 |
| 5 | 24062 |
| 6 | 147780 |
| 7 | 885190 |
| 8 | 5199560 |
| 9 | 30065870 |
| 10 | 171623328 |
| 11 | 969151710 |
| 12 | 5422863630 |
| 13 | 30105497970 |
| 14 | 165993714540 |
| 15 | 909770119914 |
| 16 | 4959840748350 |
| 17 | 26912374137150 |
| 18 | 145411035749600 |
| 19 | 782681600883950 |
| 20 | 4198276264607290 |
| 21 | 22448626776903450 |
| 22 | 119690255236279100 |
[1,10,80,570,3790,24062,147780,885190,5199560, 30065870,171623328,969151710,5422863630, 30105497970,165993714540,909770119914, 4959840748350,26912374137150,145411035749600, 782681600883950,4198276264607290, 22448626776903450,119690255236279100] |