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 | 0 |
| 1 | 1 |
| 2 | 2080 |
| 3 | 266085 |
| 4 | 8390656 |
| 5 | 122078125 |
| 6 | 1088414496 |
| 7 | 6920702425 |
| 8 | 34359869440 |
| 9 | 141215033961 |
| 10 | 500000500000 |
| 11 | 1569215074141 |
| 12 | 4458051717120 |
| 13 | 11649044974645 |
| 14 | 28346959952416 |
| 15 | 64873174640625 |
| 16 | 140737496743936 |
| 17 | 291311130683665 |
| 18 | 578415707719200 |
| 19 | 1106657483056021 |