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 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 47 |
| 5 | 227 |
| 6 | 1215 |
| 7 | 7107 |
| 8 | 44959 |
| 9 | 305091 |
| 10 | 2206399 |
| 11 | 16913987 |
| 12 | 136823263 |
| 13 | 1163490499 |
| 14 | 10366252031 |
| 15 | 96491364675 |
| 16 | 935976996127 |
| 17 | 9440144423875 |
| 18 | 98800604237119 |
| 19 | 1071092025420867 |
| 20 | 12008090971866207 |
| 21 | 139014305916844739 |
| 22 | 1659578039401022079 |
| 23 | 20405708646650507075 |