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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 1 |
| 3 | 26 |
| 4 | 46 |
| 5 | 206 |
| 6 | 433 |
| 7 | 2006 |
| 8 | 739 |
| 9 | 19034 |
| 10 | 53857 |
| 11 | 76562 |
| 12 | 435349 |
| 13 | 1357028 |
| 14 | 1290286 |
| 15 | 5539319 |
| 16 | 1267831 |
| 17 | 96236090 |
| 18 | 124187905 |
| 19 | 993503240 |
| 20 | 974457118 |
| 21 | 4308872543 |
| 22 | 13550273938 |
| 23 | 45640072286 |
| 24 | 176834220634 |
| 25 | 567385155629 |
| 26 | 1149926807260 |
| 27 | 6657548629751 |
| 28 | 22757999098060 |
[0,2,1,26,46,206,433,2006,739,19034,53857,76562, 435349,1357028,1290286,5539319,1267831,96236090, 124187905,993503240,974457118,4308872543, 13550273938,45640072286,176834220634,567385155629, 1149926807260,6657548629751,22757999098060] |