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 | 0 |
| 4 | 1 |
| 5 | 12 |
| 6 | 104 |
| 7 | 956 |
| 8 | 10037 |
| 9 | 126578 |
| 10 | 1971005 |
| 11 | 38569954 |
| 12 | 958347642 |
| 13 | 30400603560 |
| 14 | 1234260982770 |
| 15 | 64187360439352 |
| 16 | 4275470549123119 |