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 | 9 |
| 3 | 197 |
| 4 | 503 |
| 5 | 6623 |
| 6 | 17813 |
| 7 | 340527 |
| 8 | 3763087 |
| 9 | 169947523 |
| 10 | 170436583 |
| 11 | 5295982873 |
| 12 | 90208585541 |
| 13 | 3343268872217 |
| 14 | 3348036962687 |
| 15 | 144143598106421 |
| 16 | 1659445372263179 |
| 17 | 11627213232841853 |
| 18 | 3879029288899801 |
| 19 | 352907045903771 |
| 20 | 10241306344308349 |
| 21 | 208368821623076563 |