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 | 1 |
| 3 | 2 |
| 4 | 43 |
| 5 | 403 |
| 6 | 23213 |
| 7 | 118483 |
| 8 | 51997111 |
| 9 | 1842647621 |
| 10 | 327581799289 |
| 11 | 8918414485643 |
| 12 | 4670006130663971 |
| 13 | 361730891537680087 |
| 14 | 130890931830249779173 |
| 15 | 427294615628884602769 |
| 16 | 6534075316966068976316143 |
| 17 | 885163015595247156635327497 |
| 18 | 41526561745210509140249210357 |