The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 40 |
| 8 | 312 |
| 9 | 2038 |
| 10 | 9632 |
| 11 | 37248 |
| 12 | 120104 |
| 13 | 335010 |
| 14 | 835056 |
| 15 | 1897702 |
| 16 | 3998456 |
| 17 | 7907094 |
| 18 | 14818300 |
| 19 | 26512942 |
| 20 | 45562852 |
| 21 | 75580634 |
| 22 | 121520020 |
| 23 | 190031678 |
| 24 | 289879092 |
| 25 | 432420154 |
| 26 | 632159540 |
| 27 | 907376502 |
| 28 | 1280833348 |
[0,0,0,0,0,0,0,40,312,2038,9632,37248,120104, 335010,835056,1897702,3998456,7907094,14818300, 26512942,45562852,75580634,121520020,190031678, 289879092,432420154,632159540,907376502, 1280833348] |