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 | 0 |
| 2 | 3 |
| 3 | 23 |
| 4 | 290 |
| 5 | 4298 |
| 6 | 79143 |
| 7 | 1702923 |
| 8 | 42299820 |
| 9 | 1188147639 |
| 10 | 37276597020 |
| 11 | 1291633545897 |
| 12 | 48995506718702 |
| 13 | 2019395409175529 |
| 14 | 89864601931874318 |
| 15 | 4294295828157319651 |
| 16 | 219321170795303112118 |
| 17 | 11922219151375200468886 |