The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 15 |
| 4 | 58 |
| 5 | 226 |
| 6 | 882 |
| 7 | 3457 |
| 8 | 13606 |
| 9 | 53683 |
| 10 | 212090 |
| 11 | 838484 |
| 12 | 3319596 |
| 13 | 13159676 |
| 14 | 52220801 |
| 15 | 207374051 |
| 16 | 823906473 |
| 17 | 3274464556 |
| 18 | 13019414133 |
| 19 | 51790661881 |
| 20 | 206112818880 |
| 21 | 820583696869 |
| 22 | 3267935428368 |
| 23 | 13017497498243 |
| 24 | 51863262314021 |
[1,4,15,58,226,882,3457,13606,53683,212090,838484, 3319596,13159676,52220801,207374051,823906473, 3274464556,13019414133,51790661881,206112818880, 820583696869,3267935428368,13017497498243, 51863262314021] |