The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 61 |
| 4 | 908 |
| 5 | 17865 |
| 6 | 438286 |
| 7 | 12901735 |
| 8 | 443475432 |
| 9 | 17443879057 |
| 10 | 773018191610 |
| 11 | 38117147134671 |
| 12 | 2070381313048588 |
| 13 | 122841147634754185 |
| 14 | 7905667340470592070 |
| 15 | 548555101319868261655 |
| 16 | 40825552788531622527056 |
| 17 | 3244188226183716688784289 |
| 18 | 274164589130871765969460594 |
[1,1,6,61,908,17865,438286,12901735,443475432, 17443879057,773018191610,38117147134671, 2070381313048588,122841147634754185, 7905667340470592070,548555101319868261655, 40825552788531622527056,3244188226183716688784289, 274164589130871765969460594] |