The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 103 |
| 5 | 432 |
| 6 | 1858 |
| 7 | 8189 |
| 8 | 36707 |
| 9 | 166756 |
| 10 | 765805 |
| 11 | 3547921 |
| 12 | 16557837 |
| 13 | 77750578 |
| 14 | 367020564 |
| 15 | 1740351525 |
| 16 | 8285019143 |
| 17 | 39577214547 |
| 18 | 189634224541 |
| 19 | 911087840169 |
| 20 | 4387832646627 |
| 21 | 21177716642499 |
| 22 | 102413025648453 |
| 23 | 496133291135486 |
| 24 | 2407348942809524 |
| 25 | 11698125135364160 |
| 26 | 56921497653061676 |
| 27 | 277313957117770844 |
[1,2,7,26,103,432,1858,8189,36707,166756,765805, 3547921,16557837,77750578,367020564,1740351525, 8285019143,39577214547,189634224541,911087840169, 4387832646627,21177716642499,102413025648453, 496133291135486,2407348942809524, 11698125135364160,56921497653061676, 277313957117770844] |