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 | 3 |
| 3 | 7 |
| 4 | 21 |
| 5 | 51 |
| 6 | 148 |
| 7 | 365 |
| 8 | 983 |
| 9 | 2461 |
| 10 | 6360 |
| 11 | 15687 |
| 12 | 39757 |
| 13 | 97033 |
| 14 | 240425 |
| 15 | 582622 |
| 16 | 1421273 |
| 17 | 3409861 |
| 18 | 8222920 |
| 19 | 19565707 |
| 20 | 46680362 |
| 21 | 110309476 |
| 22 | 260876036 |
| 23 | 612293443 |
| 24 | 1437616751 |
| 25 | 3354111156 |
| 26 | 7823501148 |
| 27 | 18157700800 |
| 28 | 42112132458 |