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 | 384 |
| 5 | 88264 |
| 6 | 1665344 |
| 7 | 14497784 |
| 8 | 80088992 |
| 9 | 335122320 |
| 10 | 1142391712 |
| 11 | 3358831216 |
| 12 | 8772323808 |
| 13 | 20882774744 |
| 14 | 46000760736 |
| 15 | 95075730152 |
| 16 | 186010966464 |
| 17 | 347367851808 |
| 18 | 622687135680 |
| 19 | 1077266143968 |
| 20 | 1805545001664 |
| 21 | 2942598571752 |