The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 15 |
| 4 | 74 |
| 5 | 278 |
| 6 | 541 |
| 7 | 668 |
| 8 | 1320 |
| 9 | 1780 |
| 10 | 1874 |
| 11 | 4824 |
| 12 | 13310 |
| 13 | 20420 |
| 14 | 24887 |
[1,2,15,74,278,541,668,1320,1780,1874,4824,13310, 20420,24887] |