The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 3 | 3 |
| 4 | 4 |
| 5 | 6 |
| 6 | 10 |
| 7 | 21 |
| 8 | 36 |
| 9 | 81 |
| 10 | 168 |
| 11 | 360 |
| 12 | 810 |
| 13 | 1872 |
| 14 | 4480 |
| 15 | 11088 |
| 16 | 27720 |
| 17 | 71280 |
| 18 | 186368 |
| 19 | 496128 |
| 20 | 1347192 |
| 21 | 3720960 |
| 22 | 10407936 |
| 23 | 29576988 |
| 24 | 85322160 |
| 25 | 249500160 |
| 26 | 738904320 |
| 27 | 2216712960 |
| 28 | 6732000000 |
| 29 | 20680540160 |
| 30 | 64260000000 |
| 31 | 201860859375 |
[3,4,6,10,21,36,81,168,360,810,1872,4480,11088, 27720,71280,186368,496128,1347192,3720960, 10407936,29576988,85322160,249500160,738904320, 2216712960,6732000000,20680540160,64260000000, 201860859375] |