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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 15 |
| 5 | 34 |
| 6 | 83 |
| 7 | 200 |
| 8 | 683 |
| 9 | 883 |
| 10 | 2449 |
| 11 | 3332 |
| 12 | 122401 |
| 13 | 125733 |
| 14 | 373867 |
| 15 | 499600 |
| 16 | 1872667 |
| 17 | 4244934 |
| 18 | 10362535 |
| 19 | 24970004 |
| 20 | 85272547 |
| 21 | 110242551 |
| 22 | 305757649 |
| 23 | 416000200 |
| 24 | 15281764849 |
| 25 | 15697765049 |
| 26 | 46677294947 |
| 27 | 62375059996 |
| 28 | 233802474935 |
| 29 | 529980009866 |
[1,1,3,4,15,34,83,200,683,883,2449,3332,122401, 125733,373867,499600,1872667,4244934,10362535, 24970004,85272547,110242551,305757649,416000200, 15281764849,15697765049,46677294947,62375059996, 233802474935,529980009866] |