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 | 378 |
| 5 | 90027 |
| 6 | 2931831 |
| 7 | 33720354 |
| 8 | 224710119 |
| 9 | 1068797961 |
| 10 | 4037126346 |
| 11 | 12886585236 |
| 12 | 36161763120 |
| 13 | 91629683271 |
| 14 | 213681907449 |
| 15 | 465104644470 |
| 16 | 955060713621 |
| 17 | 1865654931141 |
| 18 | 3490074060228 |
| 19 | 6286011239592 |
| 20 | 10948910130774 |
| 21 | 18510503248611 |
| 22 | 30469179410667 |