The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 2 |
| 4 | 11 |
| 5 | 96 |
| 6 | 1058 |
| 7 | 14292 |
| 8 | 229273 |
| 9 | 4268583 |
| 10 | 90599501 |
| 11 | 2161197285 |
| 12 | 57273924968 |
| 13 | 1670125069883 |
| 14 | 53158796477452 |
| 15 | 1834276943996477 |
| 16 | 68212851126889959 |
| 17 | 2719975462998554200 |
| 18 | 115777392670653923870 |
| 19 | 5240030485305934701421 |
| 20 | 251291379101960875175412 |
[1,0,2,11,96,1058,14292,229273,4268583,90599501, 2161197285,57273924968,1670125069883, 53158796477452,1834276943996477,68212851126889959, 2719975462998554200,115777392670653923870, 5240030485305934701421,251291379101960875175412] |