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 | 6 |
| 3 | 30 |
| 4 | 192 |
| 5 | 1471 |
| 6 | 12637 |
| 7 | 120723 |
| 8 | 1267492 |
| 9 | 14438913 |
| 10 | 176961001 |
| 11 | 2318180239 |
| 12 | 32275104644 |
| 13 | 475285152707 |
| 14 | 7373223596299 |
| 15 | 120078748361611 |
| 16 | 2046720320727328 |
| 17 | 36414341169682417 |
| 18 | 674650306604656821 |
| 19 | 12988470845576660407 |
| 20 | 259348785562811740236 |
| 21 | 5361803880323803698731 |
| 22 | 114593610390850499426211 |