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) |
|---|---|
| 3 | 1 |
| 4 | 29 |
| 5 | 247 |
| 6 | 1300 |
| 7 | 5270 |
| 8 | 18228 |
| 9 | 56967 |
| 10 | 166681 |
| 11 | 467301 |
| 12 | 1274856 |
| 13 | 3419252 |
| 14 | 9076280 |
| 15 | 23945893 |
| 16 | 62955061 |
| 17 | 165188091 |
| 18 | 432974764 |
| 19 | 1134224458 |
| 20 | 2970340412 |
| 21 | 7777628427 |
| 22 | 20363608737 |
| 23 | 53314542953 |
| 24 | 139581703056 |
| 25 | 365432651464 |
| 26 | 956718812272 |
| 27 | 2504726904937 |
| 28 | 6557465674125 |