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 | 21280 |
| 5 | 410944 |
| 6 | 3546144 |
| 7 | 25897500 |
| 8 | 120924864 |
| 9 | 484357596 |
| 10 | 1775236608 |
| 11 | 5524384788 |
| 12 | 14504098464 |
| 13 | 40157949700 |
| 14 | 96400638496 |
| 15 | 210705045096 |
| 16 | 461362504896 |
| 17 | 967431188016 |
| 18 | 1873980413760 |
| 19 | 3612131549208 |
| 20 | 6536903000544 |