The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 13 |
| 3 | 170 |
| 4 | 3174 |
| 5 | 51272 |
| 6 | 613273 |
| 7 | 5522106 |
| 8 | 39166083 |
| 9 | 228033502 |
| 10 | 1126456193 |
| 11 | 4844806594 |
| 12 | 18514777184 |
| 13 | 63899672916 |
| 14 | 201812008205 |
| 15 | 589636064914 |
| 16 | 1608228271365 |
| 17 | 4126273835322 |
| 18 | 10023956065669 |
| 19 | 23185222993658 |
| 20 | 51305293465210 |
| 21 | 109069477192736 |
| 22 | 223570382775345 |
| 23 | 443281708368842 |
[1,2,13,170,3174,51272,613273,5522106,39166083, 228033502,1126456193,4844806594,18514777184, 63899672916,201812008205,589636064914, 1608228271365,4126273835322,10023956065669, 23185222993658,51305293465210,109069477192736, 223570382775345,443281708368842] |