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 | 107 |
| 5 | 455 |
| 6 | 1997 |
| 7 | 8943 |
| 8 | 40724 |
| 9 | 187692 |
| 10 | 873596 |
| 11 | 4098024 |
| 12 | 19348509 |
| 13 | 91843291 |
| 14 | 437942044 |
| 15 | 2096335325 |
| 16 | 10068086873 |
| 17 | 48493635634 |
| 18 | 234162526076 |
| 19 | 1133219494555 |
| 20 | 5494968832105 |
| 21 | 26691822562948 |
| 22 | 129859549681074 |
| 23 | 632680348401466 |
| 24 | 3086391197803401 |
| 25 | 15073802311868993 |
| 26 | 73697945585736510 |
[1,2,7,26,107,455,1997,8943,40724,187692,873596, 4098024,19348509,91843291,437942044,2096335325, 10068086873,48493635634,234162526076, 1133219494555,5494968832105,26691822562948, 129859549681074,632680348401466,3086391197803401, 15073802311868993,73697945585736510] |