The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 6 |
| 6 | 16 |
| 7 | 36 |
| 8 | 76 |
| 9 | 172 |
| 10 | 436 |
| 11 | 1156 |
| 12 | 3006 |
| 13 | 7606 |
| 14 | 19202 |
| 15 | 49466 |
| 16 | 130156 |
| 17 | 345356 |
| 18 | 915196 |
| 19 | 2421532 |
| 20 | 6427001 |
| 21 | 17163581 |
| 22 | 46087911 |
| 23 | 124133531 |
| 24 | 334850208 |
| 25 | 904691576 |
| 26 | 2449891276 |
| 27 | 6651540676 |
| 28 | 18100561856 |
| 29 | 49344295152 |
| 30 | 134719523056 |
| 31 | 368350942416 |
| 32 | 1008680051756 |
[1,1,1,1,2,6,16,36,76,172,436,1156,3006,7606, 19202,49466,130156,345356,915196,2421532,6427001, 17163581,46087911,124133531,334850208,904691576, 2449891276,6651540676,18100561856,49344295152, 134719523056,368350942416,1008680051756] |