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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 6 |
| 4 | 21 |
| 5 | 62 |
| 6 | 162 |
| 7 | 396 |
| 8 | 917 |
| 9 | 2036 |
| 10 | 4380 |
| 11 | 9152 |
| 12 | 18694 |
| 13 | 37380 |
| 14 | 73444 |
| 15 | 141918 |
| 16 | 270370 |
| 17 | 508178 |
| 18 | 943876 |
| 19 | 1733468 |
| 20 | 3151396 |
| 21 | 5674152 |
| 22 | 10126435 |
| 23 | 17921016 |
| 24 | 31468623 |
| 25 | 54848750 |
| 26 | 94935565 |
| 27 | 163232096 |
| 28 | 278903915 |
| 29 | 473693432 |
| 30 | 799949111 |
| 31 | 1343550666 |
| 32 | 2244807927 |
| 33 | 3731885232 |
[1,6,21,62,162,396,917,2036,4380,9152,18694,37380, 73444,141918,270370,508178,943876,1733468,3151396, 5674152,10126435,17921016,31468623,54848750, 94935565,163232096,278903915,473693432,799949111, 1343550666,2244807927,3731885232] |