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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 1 |
| 6 | 10 |
| 7 | 42 |
| 8 | 254 |
| 9 | 1331 |
| 10 | 7358 |
| 11 | 39543 |
| 12 | 212911 |
| 13 | 1135876 |
| 14 | 6039878 |
| 15 | 31975124 |
| 16 | 168790048 |
| 17 | 888664299 |
| 18 | 4669177072 |