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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 196 |
| 7 | 1072 |
| 8 | 7484 |
| 9 | 42940 |
| 10 | 261496 |
| 11 | 1477136 |
| 12 | 15219832 |
| 13 | 134828344 |
| 14 | 1488515120 |
| 15 | 13692017536 |
| 16 | 130252442896 |
| 17 | 1123580329232 |
| 18 | 14639510308384 |
| 19 | 173489066401600 |
| 20 | 2528654220104096 |
| 21 | 31472160333513376 |
| 22 | 402634734214583872 |
| 23 | 4645625988351336704 |
| 24 | 25925035549644280991680 |
[1,1,2,4,10,26,196,1072,7484,42940,261496,1477136, 15219832,134828344,1488515120,13692017536, 130252442896,1123580329232,14639510308384, 173489066401600,2528654220104096, 31472160333513376,402634734214583872, 4645625988351336704,25925035549644280991680] |