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 | 2 |
| 3 | 7 |
| 4 | 38 |
| 5 | 286 |
| 6 | 2756 |
| 7 | 32299 |
| 8 | 444998 |
| 9 | 7038898 |
| 10 | 125620652 |
| 11 | 2495811814 |
| 12 | 54618201884 |
| 13 | 1305184303996 |
| 14 | 33812846036552 |
| 15 | 943878836768947 |
| 16 | 28242424937855558 |
| 17 | 901709392642750186 |
| 18 | 30597227032818965276 |
| 19 | 1099566630423067201234 |
| 20 | 41718229482624755005748 |