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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 32 |
| 3 | 157 |
| 4 | 689 |
| 5 | 2881 |
| 6 | 11777 |
| 7 | 47617 |
| 8 | 191489 |
| 9 | 768001 |
| 10 | 3076097 |
| 11 | 12312577 |
| 12 | 49266689 |
| 13 | 197099521 |
| 14 | 788463617 |
| 15 | 3153985537 |
[1,4,32,157,689,2881,11777,47617,191489,768001, 3076097,12312577,49266689,197099521,788463617, 3153985537] |