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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 19 |
| 5 | 92 |
| 6 | 576 |
| 7 | 4156 |
| 8 | 34178 |
| 9 | 314368 |
| 10 | 3199936 |
| 11 | 35703996 |
| 12 | 433422071 |
| 13 | 5687955724 |
| 14 | 80256879068 |
| 15 | 1211781887796 |
| 16 | 19496946568898 |
| 17 | 333041104402860 |
| 18 | 6019770247224496 |
| 19 | 114794574818830716 |
| 20 | 2303332661419442569 |
| 21 | 48509766592884311132 |
| 22 | 1069983257387168051076 |
[1,2,4,19,92,576,4156,34178,314368,3199936, 35703996,433422071,5687955724,80256879068, 1211781887796,19496946568898,333041104402860, 6019770247224496,114794574818830716, 2303332661419442569,48509766592884311132, 1069983257387168051076] |