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 | 70 |
| 5 | 846 |
| 6 | 3508 |
| 7 | 12960 |
| 8 | 30064 |
| 9 | 74164 |
| 10 | 134745 |
| 11 | 266396 |