The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 22 |
| 2 | 193 |
| 3 | 1045 |
| 4 | 4180 |
| 5 | 13566 |
| 6 | 37764 |
| 7 | 93456 |
| 8 | 210705 |
| 9 | 440440 |
| 10 | 864721 |
| 11 | 1610401 |
| 12 | 2866864 |
| 13 | 4908580 |
| 14 | 8123280 |
| 15 | 13046616 |
| 16 | 20404233 |
| 17 | 31162242 |
| 18 | 46587145 |
| 19 | 68316325 |
| 20 | 98440276 |
| 21 | 139597810 |
| 22 | 195085540 |
| 23 | 268983000 |
| 24 | 366294825 |
| 25 | 493111476 |
| 26 | 656790057 |
[1,22,193,1045,4180,13566,37764,93456,210705, 440440,864721,1610401,2866864,4908580,8123280, 13046616,20404233,31162242,46587145,68316325, 98440276,139597810,195085540,268983000,366294825, 493111476,656790057] |