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 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 154 |
| 4 | 7700 |
| 5 | 731500 |
| 6 | 117771500 |
| 7 | 29678418000 |
| 8 | 11040371496000 |
| 9 | 5796195035400000 |
| 10 | 4144279450311000000 |
| 11 | 3920488359994206000000 |
| 12 | 4790836775912919732000000 |
| 13 | 7411424492337286825404000000 |
| 14 | 14266992147749277138902700000000 |
| 15 | 33670101468688294047810372000000000 |