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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 26 |
| 4 | 92 |
| 5 | 332 |
| 6 | 1220 |
| 7 | 4538 |
| 8 | 17036 |
| 9 | 64412 |
| 10 | 244928 |
| 11 | 935684 |
| 12 | 3588392 |
| 13 | 13806704 |
| 14 | 53271548 |
| 15 | 206040506 |
| 16 | 798600332 |
| 17 | 3101109164 |
| 18 | 12062148368 |
| 19 | 46986821516 |
| 20 | 183276382472 |
| 21 | 715748620424 |
| 22 | 2798274135368 |
| 23 | 10951009023716 |
| 24 | 42895901012792 |
| 25 | 168167959150232 |
| 26 | 659793819847040 |
[1,2,8,26,92,332,1220,4538,17036,64412,244928, 935684,3588392,13806704,53271548,206040506, 798600332,3101109164,12062148368,46986821516, 183276382472,715748620424,2798274135368, 10951009023716,42895901012792,168167959150232, 659793819847040] |