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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 33 |
| 4 | 145 |
| 5 | 651 |
| 6 | 2985 |
| 7 | 13880 |
| 8 | 65145 |
| 9 | 308299 |
| 10 | 1467469 |
| 11 | 7019724 |
| 12 | 33714258 |
| 13 | 162456912 |
| 14 | 785064404 |
| 15 | 3802866986 |
| 16 | 18459984428 |
| 17 | 89772495880 |
| 18 | 437275226693 |
| 19 | 2132984726293 |
| 20 | 10417766696602 |
| 21 | 50940183448809 |
| 22 | 249342704115073 |
| 23 | 1221636782170665 |
| 24 | 5990468787616224 |
| 25 | 29398246699893197 |
| 26 | 144376495827307323 |
[1,2,8,33,145,651,2985,13880,65145,308299,1467469, 7019724,33714258,162456912,785064404,3802866986, 18459984428,89772495880,437275226693, 2132984726293,10417766696602,50940183448809, 249342704115073,1221636782170665,5990468787616224, 29398246699893197,144376495827307323] |