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 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 37 |
| 5 | 632 |
| 6 | 20905 |
| 7 | 1359692 |
| 8 | 175426573 |
| 9 | 45086173824 |
| 10 | 23129393794129 |
| 11 | 23707675064224020 |
| 12 | 48577049664823958389 |
| 13 | 199020196349510773741576 |
| 14 | 1630572517436087330046884473 |
| 15 | 26716930897552073378560239594588 |
| 16 | 875487110213852689248519499248558685 |