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 | 0 |
| 1 | 1 |
| 2 | 10 |
| 3 | 114 |
| 4 | 1556 |
| 5 | 25080 |
| 6 | 468462 |
| 7 | 9971920 |
| 8 | 238551336 |
| 9 | 6339784320 |
| 10 | 185391061010 |
| 11 | 5917263922944 |
| 12 | 204735466350780 |
| 13 | 7633925334590464 |
| 14 | 305188474579874550 |
| 15 | 13023103577435351040 |
| 16 | 590850477768105474128 |
| 17 | 28401410966866912051200 |
| 18 | 1441935117039649859464986 |