The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 7 |
| 4 | 29 |
| 5 | 63 |
| 6 | 258 |
| 7 | 759 |
| 8 | 3263 |
| 9 | 12250 |
| 10 | 56330 |
| 11 | 250841 |
| 12 | 1235205 |
| 13 | 6113154 |
| 14 | 31941407 |
| 15 | 169613842 |
| 16 | 932670975 |
| 17 | 5223815423 |
| 18 | 30040926830 |
| 19 | 175918987173 |
| 20 | 1053086891249 |
| 21 | 6413469553076 |
| 22 | 39818396779256 |
| 23 | 251251607202822 |
| 24 | 1613056058498375 |
| 25 | 10514730684539068 |
[1,1,4,7,29,63,258,759,3263,12250,56330,250841, 1235205,6113154,31941407,169613842,932670975, 5223815423,30040926830,175918987173,1053086891249, 6413469553076,39818396779256,251251607202822, 1613056058498375,10514730684539068] |