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 | 12 |
| 2 | 273 |
| 3 | 25520 |
| 4 | 6778629 |
| 5 | 5132148528 |
| 6 | 11368775698280 |
| 7 | 74897449398451680 |
| 8 | 1476178370884382958936 |
| 9 | 87205387550224830516286800 |
| 10 | 15450442981642705273095610563240 |