The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 7 | 1 |
| 8 | 0 |
| 9 | 7 |
| 10 | 9 |
| 11 | 28 |
| 12 | 81 |
| 13 | 139 |
| 14 | 405 |
| 15 | 815 |
| 16 | 1771 |
| 17 | 4092 |
| 18 | 8173 |
| 19 | 18019 |
| 20 | 37609 |
| 21 | 77246 |
| 22 | 163345 |
| 23 | 331968 |
| 24 | 683631 |
| 25 | 1400777 |
| 26 | 2832362 |
| 27 | 5770056 |
| 28 | 11640546 |
| 29 | 23446366 |
| 30 | 47227530 |
| 31 | 94582628 |
| 32 | 189487950 |
| 33 | 378658714 |
| 34 | 754877809 |
| 35 | 1504215522 |
| 36 | 2990469337 |
| 37 | 5939101301 |
| 38 | 11782590061 |
| 39 | 23340439078 |
[1,0,7,9,28,81,139,405,815,1771,4092,8173,18019, 37609,77246,163345,331968,683631,1400777,2832362, 5770056,11640546,23446366,47227530,94582628, 189487950,378658714,754877809,1504215522, 2990469337,5939101301,11782590061,23340439078] |