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 | 2 |
| 3 | 18 |
| 4 | 158 |
| 5 | 1510 |
| 6 | 15962 |
| 7 | 186270 |
| 8 | 2385182 |
| 9 | 33290862 |
| 10 | 503277242 |
| 11 | 8193803926 |
| 12 | 142938943886 |
| 13 | 2659770747270 |
| 14 | 52581058479770 |
| 15 | 1100423513438766 |
| 16 | 24302677755662654 |
| 17 | 564770268904566238 |