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 | 1 |
| 2 | 12 |
| 3 | 135 |
| 4 | 2224 |
| 5 | 55725 |
| 6 | 2006316 |
| 7 | 98309827 |
| 8 | 6291829440 |
| 9 | 509638185369 |
| 10 | 50963818537900 |
| 11 | 6166622043087231 |
| 12 | 887993574204562992 |
| 13 | 150070914040571147845 |
| 14 | 29413899151951944980364 |
| 15 | 6618127309189187620585275 |
| 16 | 1694240591152432030869834496 |
| 17 | 489635530843052856921382174257 |