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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 36 |
| 3 | 102 |
| 4 | 378 |
| 5 | 1260 |
| 6 | 4374 |
| 7 | 14946 |
| 8 | 51384 |
| 9 | 176238 |
| 10 | 605022 |
| 11 | 2076288 |
| 12 | 7126302 |
| 13 | 24457806 |
| 14 | 83942100 |
| 15 | 288096942 |
| 16 | 988778082 |
| 17 | 3393583068 |
| 18 | 11647114446 |
| 19 | 39974047290 |
| 20 | 137194888728 |
| 21 | 470866430838 |
| 22 | 1616060190870 |
| 23 | 5546478488640 |
[6,36,102,378,1260,4374,14946,51384,176238,605022, 2076288,7126302,24457806,83942100,288096942, 988778082,3393583068,11647114446,39974047290, 137194888728,470866430838,1616060190870, 5546478488640] |