The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 31 |
| 2 | 930 |
| 3 | 27900 |
| 4 | 837000 |
| 5 | 25110000 |
| 6 | 753300000 |
| 7 | 22599000000 |
| 8 | 677970000000 |
| 9 | 20339100000000 |
| 10 | 610173000000000 |
| 11 | 18305190000000000 |
| 12 | 549155700000000000 |
| 13 | 16474671000000000000 |
| 14 | 494240130000000000000 |
| 15 | 14827203900000000000000 |
[1,31,930,27900,837000,25110000,753300000, 22599000000,677970000000,20339100000000, 610173000000000,18305190000000000, 549155700000000000,16474671000000000000, 494240130000000000000,14827203900000000000000] |