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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 918 |
| 3 | 6624 |
| 4 | 36450 |
| 5 | 120096 |
| 6 | 322436 |
| 7 | 764640 |
| 8 | 1637766 |
| 9 | 2912544 |
| 10 | 5591592 |
| 11 | 9160992 |
| 12 | 14668002 |
| 13 | 22913280 |
| 14 | 35544420 |
| 15 | 48529440 |
| 16 | 74114514 |
| 17 | 100230912 |
| 18 | 136486530 |
| 19 | 184801824 |
| 20 | 252809100 |
| 21 | 308852640 |
| 22 | 426995388 |
| 23 | 528491520 |
| 24 | 664053284 |
| 25 | 836215488 |
| 26 | 1070501400 |
| 27 | 1229873472 |
[1,0,918,6624,36450,120096,322436,764640,1637766, 2912544,5591592,9160992,14668002,22913280, 35544420,48529440,74114514,100230912,136486530, 184801824,252809100,308852640,426995388,528491520, 664053284,836215488,1070501400,1229873472] |