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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 14 |
| 5 | 253 |
| 6 | 5580 |
| 7 | 145333 |
| 8 | 4365570 |
| 9 | 148574713 |
| 10 | 5650204664 |
| 11 | 237457170601 |
| 12 | 10928680052310 |
| 13 | 546671459786101 |
| 14 | 29531187508501764 |
| 15 | 1713355546952888413 |
| 16 | 106257575098587583370 |
| 17 | 7014713312053733390833 |
| 18 | 491136189418859924941680 |
| 19 | 36351092730307688179075153 |
[1,0,1,14,253,5580,145333,4365570,148574713, 5650204664,237457170601,10928680052310, 546671459786101,29531187508501764, 1713355546952888413,106257575098587583370, 7014713312053733390833,491136189418859924941680, 36351092730307688179075153] |