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 | 4 |
| 2 | 18 |
| 3 | 354 |
| 4 | 7749 |
| 5 | 231799 |
| 6 | 8178855 |
| 7 | 318511707 |
| 8 | 13046748480 |
| 9 | 547969772934 |
| 10 | 23296216625352 |
| 11 | 996235422019600 |
| 12 | 42723792981743991 |
| 13 | 1834737810552367569 |
| 14 | 78843837462576032709 |
| 15 | 3389239985131275364833 |
| 16 | 145715407979704223557482 |