The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 2 |
| 3 | 34 |
| 4 | 84 |
| 5 | 1308 |
| 6 | 5424 |
| 7 | 89136 |
| 8 | 528480 |
| 9 | 9442080 |
| 10 | 73388160 |
| 11 | 1433047680 |
| 12 | 13835646720 |
| 13 | 294712992000 |
| 14 | 3407733504000 |
| 15 | 78854259456000 |
| 16 | 1063689242112000 |
| 17 | 26612469305856000 |
| 18 | 410604285708288000 |
| 19 | 11055592008050688000 |
| 20 | 192132082005405696000 |
| 21 | 5543038613901938688000 |
[2,2,34,84,1308,5424,89136,528480,9442080, 73388160,1433047680,13835646720,294712992000, 3407733504000,78854259456000,1063689242112000, 26612469305856000,410604285708288000, 11055592008050688000,192132082005405696000, 5543038613901938688000] |