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) |
|---|---|
| 0 | 1 |
| 1 | 18 |
| 2 | 207 |
| 3 | 1842 |
| 4 | 13869 |
| 5 | 92250 |
| 6 | 557214 |
| 7 | 3111624 |
| 8 | 16272972 |
| 9 | 80461694 |
| 10 | 378917667 |
| 11 | 1709416008 |
| 12 | 7422200694 |
| 13 | 31136646366 |
| 14 | 126608628735 |
| 15 | 500368588830 |
| 16 | 1926482319873 |
| 17 | 7240422289338 |
| 18 | 26610335585263 |