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 | -1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 59 |
| 4 | 449 |
| 5 | 1417 |
| 6 | 16127 |
| 7 | 429697 |
| 8 | 437705 |
| 9 | 7549093 |
| 10 | 145103527 |
| 11 | 146489197 |
| 12 | 3396112211 |
| 13 | 2442184933 |
| 14 | 7369048679 |
| 15 | 429556076057 |
| 16 | 13374954901367 |
| 17 | 13427048535167 |
| 18 | 94315062045929 |
| 19 | 3500487562166393 |
| 20 | 3510273150915593 |
| 21 | 144285489968702713 |
| 22 | 6218562602767668259 |