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 | 4 |
| 3 | 28 |
| 4 | 257 |
| 5 | 3127 |
| 6 | 46721 |
| 7 | 823673 |
| 8 | 16777474 |
| 9 | 387440175 |
| 10 | 10000060075 |
| 11 | 285311849809 |
| 12 | 8916117229571 |
| 13 | 302875173709313 |
| 14 | 11112007094026243 |
| 15 | 437893920912819179 |
| 16 | 18446744226340554502 |
| 17 | 827240262649405488542 |
| 18 | 39346408176856882188621 |