| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 4 |
| 5 | 10 |
| 6 | 15 |
| 7 | 35 |
| 8 | 56 |
| 9 | 126 |
| 10 | 210 |
| 11 | 462 |
| 12 | 792 |
| 13 | 1716 |
| 14 | 3003 |
| 15 | 6435 |
| 16 | 11440 |
| 17 | 24310 |
| 18 | 43758 |
| 19 | 92378 |
| 20 | 167960 |
| 21 | 352716 |
| 22 | 646646 |
| 23 | 1352078 |
| 24 | 2496144 |
| 25 | 5200300 |
| 26 | 9657700 |
| 27 | 20058300 |
| 28 | 37442160 |
| 29 | 77558760 |
| 30 | 145422675 |
| 31 | 300540195 |
| 32 | 565722720 |
| 33 | 1166803110 |
| 34 | 2203961430 |
| 35 | 4537567650 |
[0,1,1,3,4,10,15,35,56,126,210,462,792,1716,3003, 6435,11440,24310,43758,92378,167960,352716,646646, 1352078,2496144,5200300,9657700,20058300,37442160, 77558760,145422675,300540195,565722720,1166803110, 2203961430,4537567650] |