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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 19 |
| 5 | 56 |
| 6 | 157 |
| 7 | 428 |
| 8 | 1149 |
| 9 | 3058 |
| 10 | 8097 |
| 11 | 21370 |
| 12 | 56279 |
| 13 | 147990 |
| 14 | 388727 |
| 15 | 1020252 |
| 16 | 2676139 |
| 17 | 7016372 |
| 18 | 18389377 |
| 19 | 48184544 |
| 20 | 126229809 |
| 21 | 330635974 |
| 22 | 865940277 |
| 23 | 2267709166 |
| 24 | 5938235819 |
| 25 | 15549095466 |
| 26 | 40713244907 |
| 27 | 106599027888 |
| 28 | 279100615999 |
| 29 | 730736374568 |
| 30 | 1913175616597 |
[1,2,6,19,56,157,428,1149,3058,8097,21370,56279, 147990,388727,1020252,2676139,7016372,18389377, 48184544,126229809,330635974,865940277,2267709166, 5938235819,15549095466,40713244907,106599027888, 279100615999,730736374568,1913175616597] |