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 | 6 |
| 6 | 73 |
| 7 | 534 |
| 8 | 6095 |
| 9 | 54048 |
| 10 | 680233 |
| 11 | 7218930 |
| 12 | 102769819 |
| 13 | 1279247260 |
| 14 | 20545125053 |
| 15 | 294350830326 |
| 16 | 5287381093455 |
| 17 | 85819208861136 |
| 18 | 1708363220642257 |