The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 36 |
| 5 | 136 |
| 6 | 596 |
| 7 | 2656 |
| 8 | 13187 |
| 9 | 68226 |
| 10 | 381572 |
| 11 | 2233091 |
| 12 | 13940407 |
| 13 | 90981030 |
| 14 | 626911429 |
| 15 | 4509031955 |
| 16 | 33987610040 |
| 17 | 266668955183 |
| 18 | 2180991690286 |
| 19 | 18512572760155 |
| 20 | 163103174973092 |
| 21 | 1487228204311039 |
| 22 | 14027782824491946 |
| 23 | 136585814043190619 |
| 24 | 1371822048393658001 |
| 25 | 14190528438090988629 |
[1,3,10,36,136,596,2656,13187,68226,381572, 2233091,13940407,90981030,626911429,4509031955, 33987610040,266668955183,2180991690286, 18512572760155,163103174973092,1487228204311039, 14027782824491946,136585814043190619, 1371822048393658001,14190528438090988629] |