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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 6 |
| 5 | 47 |
| 6 | 433 |
| 7 | 4826 |
| 8 | 63344 |
| 9 | 957206 |
| 10 | 16368226 |
| 11 | 312484331 |
| 12 | 6588211317 |
| 13 | 152035645781 |
| 14 | 3811750833515 |
| 15 | 103171389227156 |
| 16 | 2998418499414228 |
| 17 | 93127351040630156 |
| 18 | 3078376326065274609 |
| 19 | 107905191218919625781 |