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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 11 |
| 5 | 51 |
| 6 | 132 |
| 7 | 771 |
| 8 | 3089 |
| 9 | 18388 |
| 10 | 96423 |
| 11 | 627529 |
| 12 | 3349018 |
| 13 | 24510305 |
| 14 | 155908651 |
| 15 | 1171494200 |
| 16 | 8647906143 |
| 17 | 71603237483 |
| 18 | 572103586280 |
| 19 | 5172888505403 |
| 20 | 43344865682187 |
| 21 | 416735802793600 |
| 22 | 3830340992280773 |
| 23 | 38239507035358011 |
| 24 | 374336654847685014 |