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 | 0 |
| 2 | 6 |
| 3 | 9 |
| 4 | 228 |
| 5 | 1095 |
| 6 | 23238 |
| 7 | 215481 |
| 8 | 4657992 |
| 9 | 66216555 |
| 10 | 1553967210 |
| 11 | 29793656013 |
| 12 | 777115661292 |
| 13 | 18608934688383 |
| 14 | 542832959656302 |
| 15 | 15470567460571905 |
| 16 | 503794462155308688 |
| 17 | 16557037363336856019 |
| 18 | 598704921471691072242 |
| 19 | 22205328374455141122165 |