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 | 7 |
| 4 | 54 |
| 5 | 484 |
| 6 | 4233 |
| 7 | 35394 |
| 8 | 293201 |
| 9 | 2464565 |
| 10 | 20943953 |
| 11 | 179718000 |
| 12 | 1556469349 |
| 13 | 13597962107 |
| 14 | 119731244640 |
| 15 | 1061769557793 |
| 16 | 9476573902533 |
| 17 | 85076550195696 |
| 18 | 767846949916102 |