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 | 5 |
| 3 | 25 |
| 4 | 80 |
| 5 | 225 |
| 6 | 605 |
| 7 | 1600 |
| 8 | 4205 |
| 9 | 11025 |
| 10 | 28880 |
| 11 | 75625 |
| 12 | 198005 |
| 13 | 518400 |
| 14 | 1357205 |
| 15 | 3553225 |
| 16 | 9302480 |
| 17 | 24354225 |
| 18 | 63760205 |
| 19 | 166926400 |
| 20 | 437019005 |
| 21 | 1144130625 |
| 22 | 2995372880 |
| 23 | 7841988025 |
| 24 | 20530591205 |
| 25 | 53749785600 |
| 26 | 140718765605 |
| 27 | 368406511225 |
| 28 | 964500768080 |