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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 14 |
| 6 | 32 |
| 7 | 72 |
| 8 | 156 |
| 9 | 336 |
| 10 | 712 |
| 11 | 1496 |
| 12 | 3120 |
| 13 | 6464 |
| 14 | 13328 |
| 15 | 27360 |
| 16 | 55968 |
| 17 | 114144 |
| 18 | 232192 |
| 19 | 471296 |
| 20 | 954816 |
| 21 | 1931264 |
| 22 | 3900800 |
| 23 | 7869312 |
| 24 | 15858432 |
| 25 | 31928832 |
| 26 | 64232704 |
| 27 | 129128960 |
| 28 | 259431936 |
| 29 | 520941056 |
| 30 | 1045557248 |
| 31 | 2097616896 |
[1,2,6,14,32,72,156,336,712,1496,3120,6464,13328, 27360,55968,114144,232192,471296,954816,1931264, 3900800,7869312,15858432,31928832,64232704, 129128960,259431936,520941056,1045557248, 2097616896] |