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) |
|---|---|
| 2 | 1 |
| 3 | 5 |
| 4 | 23 |
| 5 | 17 |
| 6 | 719 |
| 7 | 5039 |
| 8 | 1753 |
| 9 | 2999 |
| 10 | 125131 |
| 11 | 7853 |
| 12 | 479001599 |
| 13 | 3593203 |
| 14 | 87178291199 |
| 15 | 1510259 |
| 16 | 6880233439 |
| 17 | 256443711677 |
| 18 | 478749547 |
| 19 | 78143369 |
| 20 | 19499250680671 |
| 21 | 4826713612027 |
| 22 | 170006681813 |
| 23 | 498390560021687969 |
| 24 | 991459181683 |
| 25 | 114776274341482621993 |