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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 12 |
| 3 | 54 |
| 4 | 210 |
| 5 | 798 |
| 6 | 2850 |
| 7 | 10038 |
| 8 | 34410 |
| 9 | 116406 |
| 10 | 388362 |
| 11 | 1283430 |
| 12 | 4203786 |
| 13 | 13675038 |
| 14 | 44211570 |
| 15 | 142202574 |
| 16 | 455299242 |
| 17 | 1451997726 |
| 18 | 4614253122 |
| 19 | 14617620726 |
| 20 | 46177325994 |
| 21 | 145505603694 |
| 22 | 457437342546 |
| 23 | 1435074324006 |
| 24 | 4493508791754 |
| 25 | 14045385985902 |
[3,12,54,210,798,2850,10038,34410,116406,388362, 1283430,4203786,13675038,44211570,142202574, 455299242,1451997726,4614253122,14617620726, 46177325994,145505603694,457437342546, 1435074324006,4493508791754,14045385985902] |