The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 15 |
| 4 | 210 |
| 5 | 66 |
| 6 | 1820 |
| 7 | 153 |
| 8 | 7315 |
| 9 | 376740 |
| 10 | 435 |
| 11 | 1947792 |
| 12 | 91390 |
| 13 | 861 |
| 14 | 163185 |
| 15 | 20358520 |
| 16 | 40475358 |
| 17 | 1770 |
| 18 | 90858768 |
| 19 | 916895 |
| 20 | 2556 |
| 21 | 256851595 |
| 22 | 1749060 |
| 23 | 541931236 |
| 24 | 132601016340 |
| 25 | 3921225 |
| 26 | 5151 |
| 27 | 4967690 |
| 28 | 5778 |
| 29 | 6210820 |
| 30 | 1378095785451705375 |
| 31 | 11358880 |
| 32 | 7858539612 |
[2,6,15,210,66,1820,153,7315,376740,435,1947792, 91390,861,163185,20358520,40475358,1770,90858768, 916895,2556,256851595,1749060,541931236, 132601016340,3921225,5151,4967690,5778,6210820, 1378095785451705375,11358880,7858539612] |