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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 55 |
| 3 | 727 |
| 4 | 3383 |
| 5 | 19187 |
| 6 | 193087 |
| 7 | 1671315 |
| 8 | 11283382 |
| 9 | 81257447 |
| 10 | 657369214 |
| 11 | 5147569469 |
| 12 | 38210138908 |
| 13 | 288167354609 |
| 14 | 2227166744932 |
| 15 | 17081986727547 |
| 16 | 129544373848971 |
| 17 | 986096515060524 |
| 18 | 7545134870681164 |
| 19 | 57628191903916501 |
[1,55,727,3383,19187,193087,1671315,11283382, 81257447,657369214,5147569469,38210138908, 288167354609,2227166744932,17081986727547, 129544373848971,986096515060524,7545134870681164, 57628191903916501] |