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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 22 |
| 5 | 306 |
| 6 | 4016 |
| 7 | 49163 |
| 8 | 578154 |
| 9 | 6618221 |
| 10 | 74342563 |
| 11 | 823164388 |
| 12 | 9011965866 |
| 13 | 97765974368 |
| 14 | 1052666075366 |
| 15 | 11263041623194 |
| 16 | 119864659464824 |
| 17 | 1269754732725522 |
| 18 | 13396817167474205 |
| 19 | 140847445420555406 |