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) |
|---|---|
| 0 | 1 |
| 1 | 34 |
| 2 | 646 |
| 3 | 9044 |
| 4 | 104006 |
| 5 | 1040060 |
| 6 | 9360540 |
| 7 | 77558760 |
| 8 | 601080390 |
| 9 | 4407922860 |
| 10 | 30855460020 |
| 11 | 207573094680 |
| 12 | 1349225115420 |
| 13 | 8510496881880 |
| 14 | 52278766560120 |
| 15 | 313672599360720 |
| 16 | 1842826521244230 |
| 17 | 10623352887172620 |
| 18 | 60198999693978180 |
| 19 | 335847050924299320 |
| 20 | 1847158780083646260 |