The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 181 |
| 4 | 2521 |
| 5 | 35113 |
| 6 | 489061 |
| 7 | 6811741 |
| 8 | 94875313 |
| 9 | 1321442641 |
| 10 | 18405321661 |
| 11 | 256353060613 |
| 12 | 3570537526921 |
| 13 | 49731172316281 |
| 14 | 692665874901013 |
| 15 | 9647591076297901 |
| 16 | 134373609193269601 |
| 17 | 1871582937629476513 |
| 18 | 26067787517619401581 |
| 19 | 363077442309042145621 |
[1,13,181,2521,35113,489061,6811741,94875313, 1321442641,18405321661,256353060613,3570537526921, 49731172316281,692665874901013,9647591076297901, 134373609193269601,1871582937629476513, 26067787517619401581,363077442309042145621] |