The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 36 |
| 3 | 252 |
| 4 | 1168 |
| 5 | 3150 |
| 6 | 9072 |
| 7 | 16856 |
| 8 | 37440 |
| 9 | 61317 |
| 10 | 113400 |
| 11 | 161172 |
| 12 | 294336 |
| 13 | 371462 |
| 14 | 606816 |
| 15 | 793800 |
| 16 | 1198336 |
| 17 | 1420146 |
| 18 | 2207412 |
| 19 | 2476460 |
| 20 | 3679200 |
| 21 | 4247712 |
| 22 | 5802192 |
| 23 | 6436872 |
| 24 | 9434880 |
| 25 | 9844375 |
| 26 | 13372632 |
| 27 | 14900760 |
| 28 | 19687808 |
| 29 | 20511990 |
| 30 | 28576800 |
| 31 | 28630112 |
| 32 | 38347776 |
[0,1,36,252,1168,3150,9072,16856,37440,61317, 113400,161172,294336,371462,606816,793800,1198336, 1420146,2207412,2476460,3679200,4247712,5802192, 6436872,9434880,9844375,13372632,14900760, 19687808,20511990,28576800,28630112,38347776] |