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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 30 |
| 3 | 171 |
| 4 | 1044 |
| 5 | 5691 |
| 6 | 30678 |
| 7 | 159891 |
| 8 | 821100 |
| 9 | 4151511 |
| 10 | 20764590 |
| 11 | 102880755 |
| 12 | 505866804 |
| 13 | 2471159019 |
| 14 | 12004723878 |
| 15 | 58037429739 |
| 16 | 279405305676 |
| 17 | 1340130574407 |
| 18 | 6406579480446 |
| 19 | 30536794325547 |
| 20 | 145166910196116 |
| 21 | 688444702671291 |
| 22 | 3257788855054518 |
| 23 | 15385512460164963 |
[3,30,171,1044,5691,30678,159891,821100,4151511, 20764590,102880755,505866804,2471159019, 12004723878,58037429739,279405305676, 1340130574407,6406579480446,30536794325547, 145166910196116,688444702671291,3257788855054518, 15385512460164963] |