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 | 1 |
| 2 | 6 |
| 3 | 57 |
| 4 | 796 |
| 5 | 15145 |
| 6 | 374526 |
| 7 | 11669665 |
| 8 | 447595800 |
| 9 | 20733553809 |
| 10 | 1141067915290 |
| 11 | 73552752257281 |
| 12 | 5484203261135028 |
| 13 | 467864288815609465 |
| 14 | 45236104846954021014 |
| 15 | 4915818294874879570305 |
| 16 | 596044703812665607374256 |
| 17 | 80118478395137652912476449 |
| 18 | 11870487496575403846760198322 |