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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 16 |
| 3 | 44 |
| 4 | 327 |
| 5 | 1653 |
| 6 | 10135 |
| 7 | 60730 |
| 8 | 366981 |
| 9 | 2221003 |
| 10 | 13463050 |
| 11 | 81660443 |
| 12 | 495408923 |
| 13 | 3006220227 |
| 14 | 18242218796 |
| 15 | 110703174526 |
| 16 | 671804474036 |
| 17 | 4076912884571 |
| 18 | 24741148460838 |
| 19 | 150144557785977 |
| 20 | 911169851527587 |
| 21 | 5529544369303067 |
[1,16,44,327,1653,10135,60730,366981,2221003, 13463050,81660443,495408923,3006220227, 18242218796,110703174526,671804474036, 4076912884571,24741148460838,150144557785977, 911169851527587,5529544369303067] |