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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 30 |
| 6 | 106 |
| 7 | 426 |
| 8 | 1930 |
| 9 | 9690 |
| 10 | 53578 |
| 11 | 322650 |
| 12 | 2106250 |
| 13 | 14790810 |
| 14 | 111327178 |
| 15 | 893091930 |
| 16 | 7614236170 |
| 17 | 68695024410 |
| 18 | 654301474378 |
| 19 | 6557096219610 |
| 20 | 69005893630090 |
| 21 | 760519875693210 |
| 22 | 8763511069234378 |
| 23 | 105343011537811290 |
| 24 | 1319139904954848010 |