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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 6 |
| 6 | 31 |
| 7 | 106 |
| 8 | 281 |
| 9 | 946 |
| 10 | 7561 |
| 11 | 54286 |
| 12 | 281161 |
| 13 | 1207636 |
| 14 | 7997991 |
| 15 | 81996916 |
| 16 | 701522641 |
| 17 | 4580581916 |
| 18 | 29742355441 |
| 19 | 306369616636 |
| 20 | 3632198902321 |
| 21 | 34977922146721 |
| 22 | 282526761829621 |
| 23 | 2720464688299821 |
| 24 | 36188717552636881 |
| 25 | 464906756446099276 |
| 26 | 4985291127563074901 |
[1,1,1,1,1,6,31,106,281,946,7561,54286,281161, 1207636,7997991,81996916,701522641,4580581916, 29742355441,306369616636,3632198902321, 34977922146721,282526761829621,2720464688299821, 36188717552636881,464906756446099276, 4985291127563074901] |