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 | -2 |
| 1 | -1 |
| 2 | 25 |
| 3 | 341 |
| 4 | 3373 |
| 5 | 29789 |
| 6 | 250045 |
| 7 | 2048381 |
| 8 | 16581373 |
| 9 | 133432829 |
| 10 | 1070599165 |
| 11 | 8577357821 |
| 12 | 68669157373 |
| 13 | 549554511869 |
| 14 | 4397241253885 |
| 15 | 35181150961661 |
| 16 | 281462092005373 |
| 17 | 2251748274470909 |
| 18 | 18014192351838205 |