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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 12 |
| 5 | 77 |
| 6 | 382 |
| 7 | 1519 |
| 8 | 6328 |
| 9 | 37753 |
| 10 | 266522 |
| 11 | 1627131 |
| 12 | 7776516 |
| 13 | 32335877 |
| 14 | 186528214 |
| 15 | 1552283815 |
| 16 | 8927485936 |
| 17 | -15949155215 |
| 18 | -942524148046 |
| 19 | -10331486791053 |
| 20 | -66361022595972 |
| 21 | -416998255691971 |
| 22 | -6076708664221010 |
[0,1,2,3,12,77,382,1519,6328,37753,266522,1627131, 7776516,32335877,186528214,1552283815,8927485936, -15949155215,-942524148046,-10331486791053, -66361022595972,-416998255691971, -6076708664221010] |