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 | 3 |
| 3 | 22 |
| 4 | 115 |
| 5 | 1048 |
| 6 | 6418 |
| 7 | 63784 |
| 8 | 421195 |
| 9 | 4386273 |
| 10 | 30271136 |
| 11 | 324599018 |
| 12 | 2306033386 |
| 13 | 25228297188 |
| 14 | 182938978344 |
| 15 | 2030788315648 |
| 16 | 14952369357211 |
| 17 | 167836915812087 |
| 18 | 1250429798513035 |
| 19 | 14158770843121424 |
| 20 | 106483223789898776 |