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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 2 |
| 6 | 12 |
| 7 | 73 |
| 8 | 518 |
| 9 | 4192 |
| 10 | 38083 |
| 11 | 384010 |
| 12 | 4256112 |
| 13 | 51428023 |
| 14 | 672849973 |
| 15 | 9475970454 |
| 16 | 142929221023 |
| 17 | 2298778304796 |
| 18 | 39270796040272 |
| 19 | 710146895061597 |
| 20 | 13551969914092152 |
| 21 | 272168729108017392 |
| 22 | 5738224038694033364 |
[1,0,0,0,0,2,12,73,518,4192,38083,384010,4256112, 51428023,672849973,9475970454,142929221023, 2298778304796,39270796040272,710146895061597, 13551969914092152,272168729108017392, 5738224038694033364] |