| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 4 |
| 3 | 6 |
| 4 | 20 |
| 5 | 12 |
| 6 | 34 |
| 7 | 132 |
| 8 | 60 |
| 9 | 68 |
| 10 | 238 |
| 11 | 996 |
| 12 | 396 |
| 13 | 340 |
| 14 | 476 |
| 15 | 1858 |
| 16 | 8132 |
| 17 | 2988 |
| 18 | 2244 |
| 19 | 2380 |
| 20 | 3716 |
| 21 | 15510 |
| 22 | 69940 |
| 23 | 24396 |
| 24 | 16932 |
| 25 | 15708 |
| 26 | 18580 |
| 27 | 31020 |
| 28 | 135490 |
| 29 | 624132 |
| 30 | 209820 |
| 31 | 138244 |
| 32 | 118524 |
| 33 | 122628 |
| 34 | 155100 |
| 35 | 270980 |
| 36 | 1223134 |
| 37 | 5725124 |
| 38 | 1872396 |
| 39 | 1188980 |
[2,4,6,20,12,34,132,60,68,238,996,396,340,476, 1858,8132,2988,2244,2380,3716,15510,69940,24396, 16932,15708,18580,31020,135490,624132,209820, 138244,118524,122628,155100,270980,1223134, 5725124,1872396,1188980] |