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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 28 |
| 4 | 119 |
| 5 | 541 |
| 6 | 2327 |
| 7 | 10384 |
| 8 | 47491 |
| 9 | 208616 |
| 10 | 938105 |
| 11 | 4229023 |
| 12 | 18855226 |
| 13 | 84609455 |
| 14 | 379973132 |
| 15 | 1700940358 |
| 16 | 7627893865 |
| 17 | 34215621269 |
| 18 | 153337948168 |
| 19 | 687522535009 |
| 20 | 3082887354405 |
| 21 | 13820286385598 |
| 22 | 61963243406462 |
| 23 | 277818915171978 |
[1,7,28,119,541,2327,10384,47491,208616,938105, 4229023,18855226,84609455,379973132,1700940358, 7627893865,34215621269,153337948168,687522535009, 3082887354405,13820286385598,61963243406462, 277818915171978] |