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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 1 |
| 8 | 4 |
| 9 | 8 |
| 10 | 22 |
| 11 | 51 |
| 12 | 136 |
| 13 | 335 |
| 14 | 871 |
| 15 | 2217 |
| 16 | 5749 |
| 17 | 14837 |
| 18 | 38636 |
| 19 | 100622 |
| 20 | 263381 |
| 21 | 690709 |
| 22 | 1817544 |
| 23 | 4793449 |
| 24 | 12675741 |
| 25 | 33592349 |
| 26 | 89223734 |
| 27 | 237455566 |
| 28 | 633176939 |
| 29 | 1691377956 |
| 30 | 4525792533 |
| 31 | 12129365576 |
| 32 | 32556355947 |
| 33 | 87508275471 |
| 34 | 235529797422 |
[0,0,0,0,0,1,1,4,8,22,51,136,335,871,2217,5749, 14837,38636,100622,263381,690709,1817544,4793449, 12675741,33592349,89223734,237455566,633176939, 1691377956,4525792533,12129365576,32556355947, 87508275471,235529797422] |