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 | 2 |
| 2 | 32 |
| 3 | 386 |
| 4 | 4160 |
| 5 | 42242 |
| 6 | 413792 |
| 7 | 3959426 |
| 8 | 37281920 |
| 9 | 347066882 |
| 10 | 3204309152 |
| 11 | 29403732866 |
| 12 | 268588249280 |
| 13 | 2444976817922 |
| 14 | 22198569382112 |
| 15 | 201143570584706 |
| 16 | 1819787258282240 |
| 17 | 16444551185679362 |
| 18 | 148466221699088672 |
| 19 | 1339452822487618946 |