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 | 3 |
| 3 | 25 |
| 4 | 241 |
| 5 | 505 |
| 6 | 65521 |
| 7 | 131041 |
| 8 | 171865 |
| 9 | 138181681 |
| 10 | 6814407601 |
| 11 | 20174525281 |
| 12 | 45185409361 |
| 13 | 558781423201 |
| 14 | 685933859521 |
| 15 | 2601256998740401 |
| 16 | 4578654981700801 |
| 17 | 15571124394460034401 |
| 18 | 375159113055066740401 |
| 19 | 124708934978441512498801 |
| 20 | 127589793288205521873601 |
| 21 | 8644416283014847832296801 |
| 22 | 29217965124687229769336641 |