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| n | a(n) |
|---|---|
| 0 | 4 |
| 1 | 35 |
| 2 | 313 |
| 3 | 2813 |
| 4 | 25309 |
| 5 | 227765 |
| 6 | 2049853 |
| 7 | 18448613 |
| 8 | 166037389 |
| 9 | 1494336245 |
| 10 | 13449025693 |
| 11 | 121041230213 |
| 12 | 1089371069869 |
| 13 | 9804339624725 |
| 14 | 88239056614333 |
| 15 | 794151509512613 |
| 16 | 7147363585580749 |
| 17 | 64326272270161205 |
| 18 | 578936450431319773 |
| 19 | 5210428053881615813 |
| 20 | 46893852484934018029 |
[4,35,313,2813,25309,227765,2049853,18448613, 166037389,1494336245,13449025693,121041230213, 1089371069869,9804339624725,88239056614333, 794151509512613,7147363585580749, 64326272270161205,578936450431319773, 5210428053881615813,46893852484934018029] |