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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 8 |
| 8 | 18 |
| 9 | 40 |
| 10 | 98 |
| 11 | 220 |
| 12 | 533 |
| 13 | 1374 |
| 14 | 3123 |
| 15 | 7891 |
| 16 | 20758 |
| 17 | 51623 |
| 18 | 134426 |
| 19 | 350099 |
| 20 | 896154 |
| 21 | 2334491 |
| 22 | 6080296 |
| 23 | 15820903 |
| 24 | 41484494 |
| 25 | 108963192 |
| 26 | 286929392 |
| 27 | 758672816 |
| 28 | 2009479756 |
| 29 | 5336446323 |
| 30 | 14205462811 |
| 31 | 37882139049 |
[0,1,2,4,8,18,40,98,220,533,1374,3123,7891,20758, 51623,134426,350099,896154,2334491,6080296, 15820903,41484494,108963192,286929392,758672816, 2009479756,5336446323,14205462811,37882139049] |