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 | 2 |
| 2 | 4 |
| 3 | 7 |
| 4 | 13 |
| 5 | 26 |
| 6 | 58 |
| 7 | 147 |
| 8 | 423 |
| 9 | 1366 |
| 10 | 4880 |
| 11 | 19039 |
| 12 | 80281 |
| 13 | 362914 |
| 14 | 1747598 |
| 15 | 8918299 |
| 16 | 48024291 |
| 17 | 271891710 |
| 18 | 1613325844 |
| 19 | 10005690695 |
| 20 | 64702147429 |
| 21 | 435311589418 |
| 22 | 3041246276098 |
| 23 | 22024930755299 |
| 24 | 165082467634303 |
| 25 | 1278742554953574 |