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 | 5 |
| 5 | 13 |
| 6 | 36 |
| 7 | 105 |
| 8 | 321 |
| 9 | 1018 |
| 10 | 3334 |
| 11 | 11216 |
| 12 | 38635 |
| 13 | 135835 |
| 14 | 486337 |
| 15 | 1769500 |
| 16 | 6531796 |
| 17 | 24425758 |
| 18 | 92420026 |
| 19 | 353444218 |
| 20 | 1364933719 |
| 21 | 5318450239 |
| 22 | 20894505025 |
| 23 | 82713826842 |
| 24 | 329746065427 |
| 25 | 1323179962753 |
| 26 | 5341963415921 |
| 27 | 21689519880470 |
| 28 | 88533441655211 |