The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 9 |
| 3 | 57 |
| 4 | 210 |
| 5 | 585 |
| 6 | 1355 |
| 7 | 2769 |
| 8 | 5156 |
| 9 | 8945 |
| 10 | 14669 |
| 11 | 22985 |
| 12 | 34678 |
| 13 | 50681 |
| 14 | 72079 |
| 15 | 100129 |
| 16 | 136264 |
| 17 | 182113 |
| 18 | 239505 |
| 19 | 310489 |
| 20 | 397338 |
| 21 | 502569 |
| 22 | 628947 |
| 23 | 779505 |
| 24 | 957548 |
| 25 | 1166673 |
| 26 | 1410773 |
| 27 | 1694057 |
| 28 | 2021054 |
| 29 | 2396633 |
| 30 | 2826007 |
| 31 | 3314753 |
[0,1,9,57,210,585,1355,2769,5156,8945,14669,22985, 34678,50681,72079,100129,136264,182113,239505, 310489,397338,502569,628947,779505,957548,1166673, 1410773,1694057,2021054,2396633,2826007,3314753] |