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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 6 |
| 3 | 36 |
| 4 | 66 |
| 5 | 552 |
| 6 | 1248 |
| 7 | 11856 |
| 8 | 29182 |
| 9 | 294024 |
| 10 | 754712 |
| 11 | 7864656 |
| 12 | 20741082 |
| 13 | 221051304 |
| 14 | 594135812 |
| 15 | 6435862704 |
| 16 | 17543490552 |
| 17 | 192393047844 |
| 18 | 530178286952 |
| 19 | 5870767076544 |
| 20 | 16318715568296 |
| 21 | 182113708337928 |
| 22 | 509795775623836 |
[6,6,36,66,552,1248,11856,29182,294024,754712, 7864656,20741082,221051304,594135812,6435862704, 17543490552,192393047844,530178286952, 5870767076544,16318715568296,182113708337928, 509795775623836] |