The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 26 |
| 2 | 338 |
| 3 | 2938 |
| 4 | 19266 |
| 5 | 101946 |
| 6 | 454610 |
| 7 | 1761370 |
| 8 | 6065410 |
| 9 | 18892250 |
| 10 | 53972178 |
| 11 | 143027898 |
| 12 | 354870594 |
| 13 | 830764794 |
| 14 | 1847023698 |
| 15 | 3921503898 |
| 16 | 7988589570 |
| 17 | 15677993370 |
| 18 | 29746958930 |
| 19 | 54734043130 |
| 20 | 97926519106 |
| 21 | 170763634106 |
| 22 | 290835675858 |
[1,26,338,2938,19266,101946,454610,1761370, 6065410,18892250,53972178,143027898,354870594, 830764794,1847023698,3921503898,7988589570, 15677993370,29746958930,54734043130,97926519106, 170763634106,290835675858] |