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| n | a(n) |
|---|---|
| 1 | 150 |
| 2 | 486 |
| 3 | 1597 |
| 4 | 5211 |
| 5 | 16649 |
| 6 | 53553 |
| 7 | 172980 |
| 8 | 558743 |
| 9 | 1801720 |
| 10 | 5808944 |
| 11 | 18737526 |
| 12 | 60447764 |
| 13 | 194984049 |
| 14 | 628912080 |
| 15 | 2028584905 |
| 16 | 6543438398 |
| 17 | 21106550023 |
| 18 | 68080857417 |
| 19 | 219600230083 |
| 20 | 708339701336 |
| 21 | 2284812500323 |
| 22 | 7369860423165 |
[150,486,1597,5211,16649,53553,172980,558743, 1801720,5808944,18737526,60447764,194984049, 628912080,2028584905,6543438398,21106550023, 68080857417,219600230083,708339701336, 2284812500323,7369860423165] |