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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 29 |
| 4 | 142 |
| 5 | 785 |
| 6 | 4813 |
| 7 | 32240 |
| 8 | 233449 |
| 9 | 1812161 |
| 10 | 14980768 |
| 11 | 131174939 |
| 12 | 1211111629 |
| 13 | 11745451658 |
| 14 | 119255234371 |
| 15 | 1264050651953 |
| 16 | 13952113296766 |
| 17 | 160006824960725 |
| 18 | 1902825936046105 |
| 19 | 23423342243273696 |
| 20 | 297982102750214605 |
| 21 | 3911917977005948453 |
| 22 | 52926119656555824520 |
[1,2,7,29,142,785,4813,32240,233449,1812161, 14980768,131174939,1211111629,11745451658, 119255234371,1264050651953,13952113296766, 160006824960725,1902825936046105, 23423342243273696,297982102750214605, 3911917977005948453,52926119656555824520] |