The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 6 | 360 |
| 7 | 13230 |
| 8 | 137760 |
| 9 | 835380 |
| 10 | 3679200 |
| 11 | 13056120 |
| 12 | 39584160 |
| 13 | 106383420 |
| 14 | 259819560 |
| 15 | 586936350 |
| 16 | 1242521280 |
| 17 | 2489618040 |
| 18 | 4758324480 |
| 19 | 8728907040 |
| 20 | 15446635200 |
| 21 | 26477304840 |
| 22 | 44114190120 |
| 23 | 71649152190 |
| 24 | 113722852320 |
| 25 | 176771479500 |
| 26 | 269590120800 |
| 27 | 404035889400 |
| 28 | 595897192800 |
[360,13230,137760,835380,3679200,13056120, 39584160,106383420,259819560,586936350,1242521280, 2489618040,4758324480,8728907040,15446635200, 26477304840,44114190120,71649152190,113722852320, 176771479500,269590120800,404035889400, 595897192800] |