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 | 66 |
| 6 | 258 |
| 7 | 1079 |
| 8 | 4987 |
| 9 | 25195 |
| 10 | 136723 |
| 11 | 789438 |
| 12 | 4863268 |
| 13 | 31693715 |
| 14 | 217331845 |
| 15 | 1564583770 |
| 16 | 11795630861 |
| 17 | 92833623206 |
| 18 | 760811482322 |
| 19 | 6479991883525 |
| 20 | 57256139503047 |
| 21 | 523919025038279 |
| 22 | 4956976879724565 |
| 23 | 48424420955966635 |
| 24 | 487810283307069696 |