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 | 11 |
| 5 | 28 |
| 6 | 78 |
| 7 | 213 |
| 8 | 598 |
| 9 | 1670 |
| 10 | 4723 |
| 11 | 13356 |
| 12 | 37986 |
| 13 | 108193 |
| 14 | 309169 |
| 15 | 884923 |
| 16 | 2538369 |
| 17 | 7292170 |
| 18 | 20982220 |
| 19 | 60451567 |
| 20 | 174385063 |
| 21 | 503600439 |
| 22 | 1455827279 |
| 23 | 4212464112 |
| 24 | 12199373350 |
| 25 | 35357580112 |
| 26 | 102552754000 |
| 27 | 297651592188 |
| 28 | 864460682777 |
| 29 | 2512115979800 |
| 30 | 7304240074858 |