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 | 2 |
| 4 | 6 |
| 5 | 19 |
| 6 | 95 |
| 7 | 291 |
| 8 | 2037 |
| 9 | 10203 |
| 10 | 71429 |
| 11 | 357240 |
| 12 | 3929640 |
| 13 | 19648533 |
| 14 | 255430929 |
| 15 | 1788018540 |
| 16 | 16092167088 |
| 17 | 144829514049 |
| 18 | 2462101738833 |
| 19 | 17234712244012 |
| 20 | 327459532636228 |
| 21 | 2947135794083881 |
| 22 | 38312765323095109 |
| 23 | 421440418557975839 |
| 24 | 9693129626833444297 |
| 25 | 87238166641520673597 |