| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 19 |
| 6 | 98 |
| 7 | 335 |
| 8 | 1381 |
| 9 | 5164 |
| 10 | 20306 |
| 11 | 77915 |
| 12 | 303445 |
| 13 | 1175121 |
| 14 | 4574312 |
| 15 | 17794125 |
| 16 | 69379714 |
| 17 | 270671995 |
| 18 | 1057440462 |
| 19 | 4134573755 |
| 20 | 16182570293 |
| 21 | 63389522371 |
| 22 | 248511714532 |
| 23 | 974976349772 |
| 24 | 3827778946917 |
| 25 | 15037653341387 |
[1,3,8,19,98,335,1381,5164,20306,77915,303445, 1175121,4574312,17794125,69379714,270671995, 1057440462,4134573755,16182570293,63389522371, 248511714532,974976349772,3827778946917, 15037653341387] |