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 | 0 |
| 2 | 756 |
| 3 | 17472 |
| 4 | 700812 |
| 5 | 13487040 |
| 6 | 143699220 |
| 7 | 1061439552 |
| 8 | 6038839548 |
| 9 | 27868766016 |
| 10 | 109814205816 |
| 11 | 378998996544 |
| 12 | 1173180111852 |
| 13 | 3325312497024 |
| 14 | 8715279904416 |
| 15 | 21337957069632 |
| 16 | 49450420013148 |
| 17 | 108741984430464 |
| 18 | 228329201738484 |
| 19 | 461698406495424 |
| 20 | 899506102392072 |