This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 4 |
| 5 | 22 |
| 6 | 164 |
| 7 | 1599 |
| 8 | 19624 |
| 9 | 292799 |
| 10 | 5162063 |
| 11 | 105139954 |
| 12 | 2430528374 |
| 13 | 62877375426 |
| 14 | 1799698534522 |
| 15 | 56461862815496 |
| 16 | 1926534563625822 |
| 17 | 71024188655886038 |
| 18 | 2813193432059656268 |
| 19 | 119136308527407025379 |
| 20 | 5371507426340905440926 |