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 | 3 |
| 3 | 9 |
| 4 | 12 |
| 5 | 70 |
| 6 | 88 |
| 7 | 1888 |
| 8 | 4030 |
| 9 | 5830 |
| 10 | 32128 |
| 11 | 521728 |
| 12 | 1848964 |
| 13 | 8378368 |
| 14 | 34359083008 |
| 15 | 66072609790 |
| 16 | 549753192448 |
| 17 | 259708613909470 |
| 18 | 2251799645913088 |
| 19 | 9223372026117357568 |