The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 10 |
| 3 | 32 |
| 4 | 112 |
| 5 | 412 |
| 6 | 1572 |
| 7 | 6148 |
| 8 | 24494 |
| 9 | 98992 |
| 10 | 404650 |
| 11 | 1669496 |
| 12 | 6941226 |
| 13 | 29047568 |
| 14 | 122235518 |
| 15 | 516860460 |
[4,10,32,112,412,1572,6148,24494,98992,404650, 1669496,6941226,29047568,122235518,516860460] |