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 | 5 |
| 4 | 18 |
| 5 | 96 |
| 6 | 733 |
| 7 | 7501 |
| 8 | 97054 |
| 9 | 1521112 |
| 10 | 28005248 |
| 11 | 592218737 |
| 12 | 14141289480 |
| 13 | 376251253450 |
| 14 | 11036022346816 |
| 15 | 353747961265089 |
| 16 | 12301349824260074 |
| 17 | 461216257715290976 |
| 18 | 18545829116907146812 |
| 19 | 796122011317944176206 |