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 | 22 |
| 4 | 192 |
| 5 | 2046 |
| 6 | 24853 |
| 7 | 329334 |
| 8 | 4649601 |
| 9 | 68884356 |
| 10 | 1059830112 |
| 11 | 16809862992 |
| 12 | 273374177222 |
| 13 | 4539862959852 |
| 14 | 76744615270821 |
| 15 | 1317316023432372 |
| 16 | 22913901542478978 |
| 17 | 403242080061821802 |
| 18 | 7169757254509112094 |
| 19 | 128654570700129670404 |
| 20 | 2327634530912450464791 |
| 21 | 42424918919225263486322 |
| 22 | 778469235834728913157632 |
| 23 | 14371906938404203811137770 |