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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 62 |
| 4 | 666 |
| 5 | 5292 |
| 6 | 39754 |
| 7 | 307062 |
| 8 | 2456244 |
| 9 | 19825910 |
| 10 | 159305994 |
| 11 | 1274445900 |
| 12 | 10184391946 |
| 13 | 81430393590 |
| 14 | 651443132340 |
| 15 | 5212260963062 |
| 16 | 41700950994186 |
| 17 | 333607607822412 |
| 18 | 2668815050206474 |
| 19 | 21350337149539062 |
| 20 | 170802697195263924 |
| 21 | 1366424509598012150 |
[1,0,0,62,666,5292,39754,307062,2456244,19825910, 159305994,1274445900,10184391946,81430393590, 651443132340,5212260963062,41700950994186, 333607607822412,2668815050206474, 21350337149539062,170802697195263924, 1366424509598012150] |