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) |
|---|---|
| 4 | 1 |
| 5 | 40 |
| 6 | 350 |
| 7 | 3080 |
| 8 | 17129 |
| 9 | 82488 |
| 10 | 464650 |
| 11 | 1901680 |
| 12 | 8357426 |
| 13 | 35701952 |
| 14 | 159721016 |
| 15 | 627687060 |
| 16 | 2642405289 |
| 17 | 10712590392 |
| 18 | 45568675202 |
| 19 | 178738923440 |
| 20 | 736145997686 |
| 21 | 2946913512648 |
| 22 | 12311241803256 |
| 23 | 48275516469180 |
| 24 | 197284995875314 |
| 25 | 786939537437440 |
| 26 | 3254422571085400 |