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 | 6 |
| 4 | 7 |
| 5 | 78 |
| 6 | 420 |
| 7 | 6872 |
| 8 | 17253 |
| 9 | 326552 |
| 10 | 2680988 |
| 11 | 33949242 |
| 12 | 386091406 |
| 13 | 5974089338 |
| 14 | 67562271804 |
| 15 | 1708769998136 |
| 16 | 16983594666421 |
| 17 | 329723068729854 |
| 18 | 5611760457560028 |
| 19 | 121573316570762036 |
| 20 | 2099347805249971662 |
| 21 | 50720938223339101844 |
| 22 | 1008798617234428297708 |