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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 0 |
| 4 | 4 |
| 5 | 5 |
| 6 | 58 |
| 7 | 217 |
| 8 | 2035 |
| 9 | 13470 |
| 10 | 134164 |
| 11 | 1243770 |
| 12 | 14129410 |
| 13 | 164244808 |
| 14 | 2151576620 |
| 15 | 29671566836 |
| 16 | 444758323628 |
| 17 | 7055358559376 |
| 18 | 119546765395744 |
| 19 | 2139179551573104 |
| 20 | 40486788832168944 |
| 21 | 805969129348431936 |
| 22 | 16860672502118423136 |
| 23 | 369459637224850523808 |
| 24 | 8467140450141232328160 |
[1,0,4,5,58,217,2035,13470,134164,1243770, 14129410,164244808,2151576620,29671566836, 444758323628,7055358559376,119546765395744, 2139179551573104,40486788832168944, 805969129348431936,16860672502118423136, 369459637224850523808,8467140450141232328160] |