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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 19 |
| 4 | 498 |
| 5 | 2114 |
| 6 | 8351 |
| 7 | 8381 |
| 8 | 59704 |
| 9 | 233890 |
| 10 | 291963 |
| 11 | 1119181 |
| 12 | 1507131 |
| 13 | 1839746 |
| 14 | 9768399 |
| 15 | 40844982 |
| 16 | 94852115 |
| 17 | 138032741 |
| 18 | 443653568 |
| 19 | 453853664 |
| 20 | 2491818901 |
[1,2,19,498,2114,8351,8381,59704,233890,291963, 1119181,1507131,1839746,9768399,40844982,94852115, 138032741,443653568,453853664,2491818901] |