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 | 2 |
| 5 | 33 |
| 6 | 557 |
| 7 | 6721 |
| 8 | 71248 |
| 9 | 719531 |
| 10 | 6996756 |
| 11 | 66745265 |
| 12 | 629634308 |
| 13 | 5900013825 |
| 14 | 55082083947 |
| 15 | 513336390285 |
| 16 | 4781421106831 |
| 17 | 44546412612392 |
| 18 | 415327075240821 |