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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 14 |
| 4 | 47 |
| 5 | 153 |
| 6 | 486 |
| 7 | 1516 |
| 8 | 4669 |
| 9 | 14255 |
| 10 | 43268 |
| 11 | 130818 |
| 12 | 394491 |
| 13 | 1187557 |
| 14 | 3570850 |
| 15 | 10728920 |
| 16 | 32219513 |
| 17 | 96724059 |
| 18 | 290303232 |
| 19 | 871171822 |
| 20 | 2614039735 |
| 21 | 7843167761 |
| 22 | 23531600414 |
| 23 | 70598995524 |
| 24 | 211805375157 |
| 25 | 635432902663 |
| 26 | 1906332262396 |
| 27 | 5719063896026 |
| 28 | 17157325905779 |
| 29 | 51472246152765 |
[0,1,4,14,47,153,486,1516,4669,14255,43268,130818, 394491,1187557,3570850,10728920,32219513,96724059, 290303232,871171822,2614039735,7843167761, 23531600414,70598995524,211805375157,635432902663, 1906332262396,5719063896026,17157325905779, 51472246152765] |