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 | 1 |
| 2 | 5 |
| 3 | 49 |
| 4 | 793 |
| 5 | 19361 |
| 6 | 672061 |
| 7 | 31721425 |
| 8 | 1963804529 |
| 9 | 154746407233 |
| 10 | 15136503333301 |
| 11 | 1799712380844401 |
| 12 | 255578390749947145 |
| 13 | 42713809784784354529 |
| 14 | 8296411053128532892013 |
| 15 | 1852797862395580239567121 |
| 16 | 471358206112272764630500321 |
| 17 | 135500644700064476406317390465 |