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 | 1 |
| 3 | 128 |
| 4 | 624 |
| 5 | 28417 |
| 6 | 286395 |
| 7 | 8261289 |
| 8 | 114243216 |
| 9 | 2688307514 |
| 10 | 43598351250 |
| 11 | 928370853748 |
| 12 | 16331387665387 |
| 13 | 330593938169845 |
| 14 | 6062963019120077 |
| 15 | 119575303856316650 |
| 16 | 2240422461856052342 |
| 17 | 43592076562463162280 |
| 18 | 825830699757513748579 |
| 19 | 15955080499901505066753 |