The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 30 |
| 2 | 198 |
| 3 | 1330 |
| 4 | 8990 |
| 5 | 60998 |
| 6 | 414910 |
| 7 | 2827298 |
| 8 | 19292018 |
| 9 | 131778306 |
| 10 | 900905082 |
| 11 | 6163326750 |
| 12 | 42189104748 |
| 13 | 288930449010 |
| 14 | 1979525532152 |
| 15 | 13566774085658 |
| 16 | 93007355721960 |
| 17 | 637770486097522 |
| 18 | 4374235089178342 |
| 19 | 30006615117630438 |
[1,30,198,1330,8990,60998,414910,2827298,19292018, 131778306,900905082,6163326750,42189104748, 288930449010,1979525532152,13566774085658, 93007355721960,637770486097522,4374235089178342, 30006615117630438] |