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 | 7 |
| 2 | 48 |
| 3 | 325 |
| 4 | 2183 |
| 5 | 14588 |
| 6 | 97161 |
| 7 | 645719 |
| 8 | 4285240 |
| 9 | 28411789 |
| 10 | 188257719 |
| 11 | 1246893028 |
| 12 | 8256349457 |
| 13 | 54659946215 |
| 14 | 361825274112 |
| 15 | 2394939574997 |
| 16 | 15851402375719 |
| 17 | 104912178457996 |
| 18 | 694343294142105 |
| 19 | 4595323060281271 |
| 20 | 30412598132972936 |
| 21 | 201274210714545437 |