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 | 3 |
| 3 | 3 |
| 4 | 3 |
| 5 | 992 |
| 6 | 3 |
| 7 | 3 |
| 8 | 3 |
| 9 | 877681 |
| 10 | 195496587 |
| 11 | 3 |
| 12 | 36787319437 |
| 13 | 1423919640546 |
| 14 | 3542630063906 |
| 15 | 77319946053101 |
| 16 | 6458069995222223 |
| 17 | 168313041233693968 |
| 18 | 3 |
| 19 | 139200566017647400916 |
| 20 | 207875641949796659481 |