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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 10 |
| 6 | 20 |
| 7 | 156 |
| 8 | 273 |
| 9 | 1986 |
| 10 | 3358 |
| 11 | 23742 |
| 12 | 39736 |
| 13 | 277178 |
| 14 | 462794 |
| 15 | 3205896 |
| 16 | 5355743 |
| 17 | 36963722 |
| 18 | 61856394 |
| 19 | 426075994 |
| 20 | 714515312 |
| 21 | 4916833424 |
| 22 | 8263479072 |
| 23 | 56840484232 |
| 24 | 95733461792 |
| 25 | 658460090994 |
| 26 | 1111253958664 |
| 27 | 7644360501390 |
| 28 | 12925362323004 |
| 29 | 88938175307354 |
[0,0,0,1,10,20,156,273,1986,3358,23742,39736, 277178,462794,3205896,5355743,36963722,61856394, 426075994,714515312,4916833424,8263479072, 56840484232,95733461792,658460090994, 1111253958664,7644360501390,12925362323004, 88938175307354] |