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) |
|---|---|
| 0 | 1 |
| 1 | 28 |
| 2 | 336 |
| 3 | 2520 |
| 4 | 13860 |
| 5 | 60984 |
| 6 | 226512 |
| 7 | 736164 |
| 8 | 2147145 |
| 9 | 5725720 |
| 10 | 14158144 |
| 11 | 32821152 |
| 12 | 71954064 |
| 13 | 150233760 |
| 14 | 300467520 |
| 15 | 578399976 |
| 16 | 1075994073 |
| 17 | 1941008916 |
| 18 | 3405278800 |
| 19 | 5824819000 |
| 20 | 9735768900 |
| 21 | 15931258200 |
| 22 | 25565576400 |
| 23 | 40293571500 |
| 24 | 62455035825 |
| 25 | 95315993136 |