The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 10 |
| 3 | 40 |
| 4 | 172 |
| 5 | 761 |
| 6 | 3484 |
| 7 | 16219 |
| 8 | 76413 |
| 9 | 364192 |
| 10 | 1748227 |
| 11 | 8443769 |
| 12 | 40994937 |
| 13 | 199796255 |
| 14 | 977047346 |
| 15 | 4791306327 |
| 16 | 23549578328 |
| 17 | 115979651288 |
| 18 | 572148949214 |
| 19 | 2826591966146 |
| 20 | 13981867047153 |
| 21 | 69237078504933 |
| 22 | 343183608015103 |
| 23 | 1702466147416325 |
| 24 | 8451820517056851 |
| 25 | 41986153381168419 |
| 26 | 208695902977464969 |
[1,3,10,40,172,761,3484,16219,76413,364192, 1748227,8443769,40994937,199796255,977047346, 4791306327,23549578328,115979651288,572148949214, 2826591966146,13981867047153,69237078504933, 343183608015103,1702466147416325,8451820517056851, 41986153381168419,208695902977464969] |