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 | 1 |
| 1 | 5 |
| 2 | 17 |
| 3 | 57 |
| 4 | 197 |
| 5 | 701 |
| 6 | 2549 |
| 7 | 9413 |
| 8 | 35153 |
| 9 | 132393 |
| 10 | 501905 |
| 11 | 1912769 |
| 12 | 7321081 |
| 13 | 28122281 |
| 14 | 108355481 |
| 15 | 418590521 |
| 16 | 1620751301 |
| 17 | 6287963741 |
| 18 | 24438234341 |
| 19 | 95128761941 |
| 20 | 370821819581 |
| 21 | 1447337568461 |
| 22 | 5655535495901 |
| 23 | 22122396951101 |
| 24 | 86617604317301 |
| 25 | 339438817192805 |
| 26 | 1331275883089013 |