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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 60 |
| 4 | 594 |
| 5 | 3040 |
| 6 | 10875 |
| 7 | 30996 |
| 8 | 75460 |
| 9 | 163584 |
| 10 | 324405 |
| 11 | 599500 |
| 12 | 1046166 |
| 13 | 1740960 |
| 14 | 2783599 |
| 15 | 4301220 |
| 16 | 6453000 |
| 17 | 9435136 |
| 18 | 13486185 |
| 19 | 18892764 |
| 20 | 25995610 |
| 21 | 35196000 |
| 22 | 46962531 |
| 23 | 61838260 |
| 24 | 80448204 |
| 25 | 103507200 |
| 26 | 131828125 |
| 27 | 166330476 |
| 28 | 208049310 |
| 29 | 258144544 |
| 30 | 317910615 |
[0,0,1,60,594,3040,10875,30996,75460,163584, 324405,599500,1046166,1740960,2783599,4301220, 6453000,9435136,13486185,18892764,25995610, 35196000,46962531,61838260,80448204,103507200, 131828125,166330476,208049310,258144544,317910615] |