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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 21 |
| 2 | 322 |
| 3 | 4362 |
| 4 | 55363 |
| 5 | 675423 |
| 6 | 8027524 |
| 7 | 93683604 |
| 8 | 1078947205 |
| 9 | 12304267305 |
| 10 | 139269572806 |
| 11 | 1567268992926 |
| 12 | 17557692150727 |
| 13 | 195994212714867 |
| 14 | 2181672731375368 |
| 15 | 24230027568735528 |
| 16 | 268614950968549129 |
| 17 | 2973526290066165309 |
| 18 | 32877645655436942410 |
| 19 | 363173810392188482610 |
[1,21,322,4362,55363,675423,8027524,93683604, 1078947205,12304267305,139269572806,1567268992926, 17557692150727,195994212714867,2181672731375368, 24230027568735528,268614950968549129, 2973526290066165309,32877645655436942410, 363173810392188482610] |