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| n | a(n) |
|---|---|
| 1 | 409 |
| 2 | 1001 |
| 3 | 2598 |
| 4 | 6973 |
| 5 | 19701 |
| 6 | 55849 |
| 7 | 153286 |
| 8 | 432380 |
| 9 | 1232980 |
| 10 | 3453740 |
| 11 | 9694328 |
| 12 | 27459576 |
| 13 | 77441354 |
| 14 | 217625342 |
| 15 | 613977178 |
| 16 | 1733263382 |
| 17 | 4880225452 |
| 18 | 13751170422 |
| 19 | 38794513220 |
| 20 | 109345894200 |
| 21 | 308089966994 |
| 22 | 868658498318 |
| 23 | 2449053719350 |
[409,1001,2598,6973,19701,55849,153286,432380, 1232980,3453740,9694328,27459576,77441354, 217625342,613977178,1733263382,4880225452, 13751170422,38794513220,109345894200,308089966994, 868658498318,2449053719350] |