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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 12 |
| 3 | 48 |
| 4 | 216 |
| 5 | 936 |
| 6 | 4104 |
| 7 | 17928 |
| 8 | 78408 |
| 9 | 342792 |
| 10 | 1498824 |
| 11 | 6553224 |
| 12 | 28652616 |
| 13 | 125277192 |
| 14 | 547747272 |
| 15 | 2394904968 |
| 16 | 10471198536 |
| 17 | 45783025416 |
| 18 | 200176267464 |
| 19 | 875226954888 |
| 20 | 3826738469448 |
| 21 | 16731577137672 |
| 22 | 73155162229704 |
| 23 | 319854949515144 |
| 24 | 1398495821923656 |
[1,2,12,48,216,936,4104,17928,78408,342792, 1498824,6553224,28652616,125277192,547747272, 2394904968,10471198536,45783025416,200176267464, 875226954888,3826738469448,16731577137672, 73155162229704,319854949515144,1398495821923656] |