| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 36 |
| 5 | 106 |
| 6 | 249 |
| 7 | 613 |
| 8 | 1732 |
| 9 | 8028 |
| 10 | 23348 |
| 11 | 69370 |
| 12 | 210807 |
| 13 | 634839 |
| 14 | 1893582 |
| 15 | 5686389 |
| 16 | 17031777 |
| 17 | 51073675 |
| 18 | 153185957 |
| 19 | 459516225 |
| 20 | 1378707224 |
| 21 | 4135278456 |
| 22 | 12406199367 |
| 23 | 37216010685 |
| 24 | 111651745638 |
| 25 | 334951946950 |
| 26 | 1004855123675 |
| 27 | 3014552251123 |
| 28 | 9043690122807 |
[1,2,4,12,36,106,249,613,1732,8028,23348,69370, 210807,634839,1893582,5686389,17031777,51073675, 153185957,459516225,1378707224,4135278456, 12406199367,37216010685,111651745638,334951946950, 1004855123675,3014552251123,9043690122807] |
