The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 43 |
| 3 | 234 |
| 4 | 1146 |
| 5 | 5150 |
| 6 | 21652 |
| 7 | 86608 |
| 8 | 334072 |
| 9 | 1249768 |
| 10 | 4557284 |
| 11 | 16266830 |
| 12 | 57031078 |
| 13 | 196933710 |
| 14 | 671224467 |
| 15 | 2262089361 |
| 16 | 7548882573 |
| 17 | 24975936372 |
| 18 | 82012110724 |
| 19 | 267505920876 |
| 20 | 867390073384 |
[7,43,234,1146,5150,21652,86608,334072,1249768, 4557284,16266830,57031078,196933710,671224467, 2262089361,7548882573,24975936372,82012110724, 267505920876,867390073384] |