The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 4 |
| 6 | 16 |
| 7 | 56 |
| 8 | 188 |
| 9 | 608 |
| 10 | 1922 |
| 11 | 5972 |
| 12 | 18326 |
| 13 | 55704 |
| 14 | 168090 |
| 15 | 504348 |
| 16 | 1506531 |
| 17 | 4484208 |
| 18 | 13309572 |
| 19 | 39414568 |
| 20 | 116508361 |
| 21 | 343890196 |
| 22 | 1013840836 |
| 23 | 2986129168 |
| 24 | 8788591801 |
| 25 | 25850576024 |
| 26 | 76000747820 |
| 27 | 223361900840 |
| 28 | 656270632875 |
| 29 | 1927845012756 |
[1,4,16,56,188,608,1922,5972,18326,55704,168090, 504348,1506531,4484208,13309572,39414568, 116508361,343890196,1013840836,2986129168, 8788591801,25850576024,76000747820,223361900840, 656270632875,1927845012756] |