The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 9 |
| 4 | 576 |
| 5 | 6900 |
| 6 | 44100 |
| 7 | 196245 |
| 8 | 686784 |
| 9 | 2023056 |
| 10 | 5232600 |
| 11 | 12224025 |
| 12 | 26310240 |
| 13 | 52936884 |
| 14 | 100663836 |
| 15 | 182452725 |
| 16 | 317318400 |
| 17 | 532407360 |
| 18 | 865571184 |
| 19 | 1368508041 |
| 20 | 2110550400 |
| 21 | 3183182100 |
| 22 | 4705372980 |
| 23 | 6829824309 |
| 24 | 9750223296 |
| 25 | 13709610000 |
| 26 | 19009965000 |
| 27 | 26023131225 |
[0,0,9,576,6900,44100,196245,686784,2023056, 5232600,12224025,26310240,52936884,100663836, 182452725,317318400,532407360,865571184, 1368508041,2110550400,3183182100,4705372980, 6829824309,9750223296,13709610000,19009965000, 26023131225] |