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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 546 |
| 4 | 2730 |
| 5 | 13650 |
| 6 | 51870 |
| 7 | 101010 |
| 8 | 199290 |
| 9 | 505050 |
| 10 | 881790 |
| 11 | 996450 |
| 12 | 1919190 |
| 13 | 32626230 |
| 14 | 140100870 |
| 15 | 654443790 |
| 16 | 865554690 |