The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 19 |
| 3 | 301 |
| 4 | 4659 |
| 5 | 73651 |
| 6 | 1208849 |
| 7 | 20736801 |
| 8 | 372683159 |
| 9 | 7020426511 |
| 10 | 138543438429 |
| 11 | 2861318625661 |
| 12 | 61767341913539 |
| 13 | 1391789835244251 |
| 14 | 32689488282841529 |
| 15 | 799220290375798681 |
| 16 | 20312800343333343279 |
| 17 | 535995638431063608871 |
| 18 | 14665906835087251866389 |
[0,1,19,301,4659,73651,1208849,20736801,372683159, 7020426511,138543438429,2861318625661, 61767341913539,1391789835244251,32689488282841529, 799220290375798681,20312800343333343279, 535995638431063608871,14665906835087251866389] |