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 | 8 |
| 5 | 16 |
| 6 | 36 |
| 7 | 80 |
| 8 | 194 |
| 9 | 505 |
| 10 | 1439 |
| 11 | 4559 |
| 12 | 16580 |
| 13 | 70491 |
| 14 | 361339 |
| 15 | 2278637 |
| 16 | 17745061 |
| 17 | 166540680 |
| 18 | 1794040168 |
| 19 | 20987476447 |
| 20 | 254684454328 |
| 21 | 3107605995993 |
| 22 | 37418101305011 |
| 23 | 439995775004885 |
| 24 | 5025781692126252 |
| 25 | 55627454599068011 |
| 26 | 596148004493419480 |
| 27 | 6186335017615750870 |
| 28 | 62196701669630203157 |