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 | 2 |
| 2 | 16 |
| 3 | 188 |
| 4 | 2896 |
| 5 | 50452 |
| 6 | 953056 |
| 7 | 19003476 |
| 8 | 394397776 |
| 9 | 8439756848 |
| 10 | 185033251616 |
| 11 | 4137181680700 |
| 12 | 94020327215200 |
| 13 | 2166105078791448 |
| 14 | 50489825388328608 |
| 15 | 1188777328563914488 |
| 16 | 28236363841989180496 |
| 17 | 675879582290807439796 |
| 18 | 16289254212704277185152 |