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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 10 |
| 2 | 34 |
| 3 | 116 |
| 4 | 396 |
| 5 | 1352 |
| 6 | 4616 |
| 7 | 15760 |
| 8 | 53808 |
| 9 | 183712 |
| 10 | 627232 |
| 11 | 2141504 |
| 12 | 7311552 |
| 13 | 24963200 |
| 14 | 85229696 |
| 15 | 290992384 |
| 16 | 993510144 |
| 17 | 3392055808 |
| 18 | 11581202944 |
| 19 | 39540700160 |
| 20 | 135000394752 |
| 21 | 460920178688 |
| 22 | 1573679925248 |
| 23 | 5372879343616 |
| 24 | 18344157523968 |
| 25 | 62630871408640 |
[3,10,34,116,396,1352,4616,15760,53808,183712, 627232,2141504,7311552,24963200,85229696, 290992384,993510144,3392055808,11581202944, 39540700160,135000394752,460920178688, 1573679925248,5372879343616,18344157523968, 62630871408640] |