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 | 4 |
| 5 | 120 |
| 6 | 1140 |
| 7 | 6545 |
| 8 | 27720 |
| 9 | 95284 |
| 10 | 280840 |
| 11 | 735130 |
| 12 | 1750540 |
| 13 | 3858140 |
| 14 | 7971964 |
| 15 | 15596035 |
| 16 | 29112720 |
| 17 | 52174360 |
| 18 | 90223760 |
| 19 | 151173044 |
| 20 | 246274580 |
| 21 | 391222160 |
| 22 | 607525380 |
| 23 | 924205205 |
| 24 | 1379864024 |
| 25 | 2025189100 |
| 26 | 2925954200 |
| 27 | 4166590350 |