The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 3 |
| 5 | 15 |
| 6 | 10 |
| 7 | 70 |
| 8 | 35 |
| 9 | 315 |
| 10 | 126 |
| 11 | 1386 |
| 12 | 462 |
| 13 | 6006 |
| 14 | 1716 |
| 15 | 25740 |
| 16 | 6435 |
| 17 | 109395 |
| 18 | 24310 |
| 19 | 461890 |
| 20 | 92378 |
| 21 | 1939938 |
| 22 | 352716 |
| 23 | 8112468 |
| 24 | 1352078 |
| 25 | 33801950 |
| 26 | 5200300 |
| 27 | 140408100 |
| 28 | 20058300 |
| 29 | 581690700 |
| 30 | 77558760 |
| 31 | 2404321560 |
| 32 | 300540195 |
| 33 | 9917826435 |
| 34 | 1166803110 |
| 35 | 40838108850 |
[1,1,1,3,3,15,10,70,35,315,126,1386,462,6006,1716, 25740,6435,109395,24310,461890,92378,1939938, 352716,8112468,1352078,33801950,5200300,140408100, 20058300,581690700,77558760,2404321560,300540195, 9917826435,1166803110,40838108850] |