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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 132 |
| 3 | 2196 |
| 4 | 16912 |
| 5 | 78150 |
| 6 | 289872 |
| 7 | 823592 |
| 8 | 2164800 |
| 9 | 4802733 |
| 10 | 10315800 |
| 11 | 19487292 |
| 12 | 37138752 |
| 13 | 62748686 |
| 14 | 108714144 |
| 15 | 171617400 |
| 16 | 277094656 |
| 17 | 410338962 |
| 18 | 633960756 |
| 19 | 893872100 |
| 20 | 1321672800 |
| 21 | 1808608032 |
| 22 | 2572322544 |
| 23 | 3404825976 |
| 24 | 4753900800 |
| 25 | 6105469375 |
| 26 | 8282826552 |
[0,1,132,2196,16912,78150,289872,823592,2164800, 4802733,10315800,19487292,37138752,62748686, 108714144,171617400,277094656,410338962,633960756, 893872100,1321672800,1808608032,2572322544, 3404825976,4753900800,6105469375,8282826552] |