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| n | a(n) |
|---|---|
| 1 | 21 |
| 2 | 348 |
| 3 | 227 |
| 4 | 15694 |
| 5 | 72678 |
| 6 | 1177545 |
| 7 | 25625864 |
| 8 | 356815204 |
| 9 | 6737133411 |
| 10 | 128991872363 |
| 11 | 2248913609180 |
| 12 | 41521302814764 |
| 13 | 780978669606475 |
| 14 | 14143827089702850 |
| 15 | 261123558952089715 |
| 16 | 4852602843700239495 |
[21,348,227,15694,72678,1177545,25625864, 356815204,6737133411,128991872363,2248913609180, 41521302814764,780978669606475,14143827089702850, 261123558952089715,4852602843700239495] |