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 | 1 |
| 4 | 3 |
| 5 | 6 |
| 6 | 26 |
| 7 | 85 |
| 8 | 476 |
| 9 | 2171 |
| 10 | 14905 |
| 11 | 87153 |
| 12 | 708825 |
| 13 | 5053464 |
| 14 | 47514180 |
| 15 | 399542814 |
| 16 | 4264132468 |
| 17 | 41306091312 |
| 18 | 493337571005 |
| 19 | 5408829555639 |
| 20 | 71476985762027 |
| 21 | 874870165668858 |
| 22 | 12673922434134249 |
| 23 | 171294209823727623 |
| 24 | 2699365743596908540 |
| 25 | 39925463781029750810 |