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 | 72 |
| 2 | 2916 |
| 3 | 87480 |
| 4 | 2165130 |
| 5 | 46766808 |
| 6 | 911952756 |
| 7 | 16415149608 |
| 8 | 277005649635 |
| 9 | 4432090394160 |
| 10 | 67810983030648 |
| 11 | 998670840996816 |
| 12 | 14231059484204628 |
| 13 | 197045439012064080 |
| 14 | 2660113426662865080 |
| 15 | 35113497231949819056 |
| 16 | 454280870438350784037 |
| 17 | 5772039294981398197176 |