The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 70 |
| 1 | 21 |
| 2 | 30 |
| 3 | 70 |
| 4 | 210 |
| 5 | 735 |
| 6 | 2856 |
| 7 | 11970 |
| 8 | 53130 |
| 9 | 246675 |
| 10 | 1187550 |
| 11 | 5890248 |
| 12 | 29954680 |
| 13 | 155602020 |
| 14 | 823184880 |
| 15 | 4424618730 |
| 16 | 24116031162 |
| 17 | 133072694475 |
| 18 | 742405558650 |
| 19 | 4182821562150 |
| 20 | 23776769743650 |
| 21 | 136248095712855 |
| 22 | 786482994679200 |
[70,21,30,70,210,735,2856,11970,53130,246675, 1187550,5890248,29954680,155602020,823184880, 4424618730,24116031162,133072694475,742405558650, 4182821562150,23776769743650,136248095712855, 786482994679200] |