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 | 4 |
| 2 | 27 |
| 3 | 208 |
| 4 | 1724 |
| 5 | 14952 |
| 6 | 133581 |
| 7 | 1217976 |
| 8 | 11269359 |
| 9 | 105423292 |
| 10 | 994691555 |
| 11 | 9449623872 |
| 12 | 90277420688 |
| 13 | 866526247552 |
| 14 | 8350536475896 |
| 15 | 80748593332416 |
| 16 | 783157950294876 |
| 17 | 7615517087165040 |
| 18 | 74225719019229060 |
| 19 | 724945200854844480 |
| 20 | 7093481177196998640 |