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 | 0 |
| 3 | 1 |
| 4 | 10 |
| 5 | 253 |
| 6 | 12058 |
| 7 | 1052443 |
| 8 | 169488200 |
| 9 | 51045018089 |
| 10 | 29184193354806 |
| 11 | 32122530765469967 |
| 12 | 68867427921051098084 |
| 13 | 290155706369032525823085 |
| 14 | 2417761578629525173499004146 |
| 15 | 40013923790443379076988789688611 |
| 16 | 1318910080173114018084245406769861936 |