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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 13 |
| 5 | 36 |
| 6 | 94 |
| 7 | 232 |
| 8 | 557 |
| 9 | 1300 |
| 10 | 2986 |
| 11 | 6744 |
| 12 | 15074 |
| 13 | 33320 |
| 14 | 73116 |
| 15 | 159184 |
| 16 | 344701 |
| 17 | 742068 |
| 18 | 1590898 |
| 19 | 3395320 |
| 20 | 7222550 |
| 21 | 15308920 |
| 22 | 32362276 |
| 23 | 68213424 |
| 24 | 143463378 |
| 25 | 300999816 |
| 26 | 630353764 |
| 27 | 1317415792 |
| 28 | 2748991012 |
| 29 | 5726300880 |
| 30 | 11911913912 |
| 31 | 24742452128 |
| 32 | 51331847709 |
[0,0,1,4,13,36,94,232,557,1300,2986,6744,15074, 33320,73116,159184,344701,742068,1590898,3395320, 7222550,15308920,32362276,68213424,143463378, 300999816,630353764,1317415792,2748991012, 5726300880,11911913912,24742452128,51331847709] |