The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 30 |
| 7 | 102 |
| 8 | 485 |
| 9 | 1209 |
| 10 | 3622 |
| 11 | 7472 |
| 12 | 18761 |
| 13 | 32668 |
| 14 | 68364 |
| 15 | 113299 |
| 16 | 211048 |
| 17 | 315291 |
| 18 | 560656 |
| 19 | 783765 |
| 20 | 1302666 |
| 21 | 1793022 |
| 22 | 2758386 |
| 23 | 3624837 |
| 24 | 5631414 |
| 25 | 7012350 |
| 26 | 10247902 |
| 27 | 13024865 |
| 28 | 18346867 |
| 29 | 22183836 |
| 30 | 31716850 |
| 31 | 37062779 |
| 32 | 51151518 |
| 33 | 61104631 |
[0,0,0,1,3,30,102,485,1209,3622,7472,18761,32668, 68364,113299,211048,315291,560656,783765,1302666, 1793022,2758386,3624837,5631414,7012350,10247902, 13024865,18346867,22183836,31716850,37062779, 51151518,61104631] |