The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 30 |
| 4 | 122 |
| 5 | 508 |
| 6 | 2163 |
| 7 | 9336 |
| 8 | 40804 |
| 9 | 179887 |
| 10 | 799120 |
| 11 | 3571698 |
| 12 | 16048114 |
| 13 | 72428799 |
| 14 | 328167457 |
| 15 | 1491978164 |
| 16 | 6803716892 |
| 17 | 31110321096 |
| 18 | 142600055057 |
| 19 | 655074921487 |
| 20 | 3015313208782 |
| 21 | 13904953770666 |
| 22 | 64229950295692 |
| 23 | 297152727581176 |
| 24 | 1376720785809034 |
| 25 | 6386921652633456 |
| 26 | 29667247964299526 |
| 27 | 137964512850757605 |
[1,2,8,30,122,508,2163,9336,40804,179887,799120, 3571698,16048114,72428799,328167457,1491978164, 6803716892,31110321096,142600055057,655074921487, 3015313208782,13904953770666,64229950295692, 297152727581176,1376720785809034,6386921652633456, 29667247964299526,137964512850757605] |