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 | 9 |
| 2 | 133 |
| 3 | 1853 |
| 4 | 26117 |
| 5 | 367389 |
| 6 | 5169809 |
| 7 | 72744121 |
| 8 | 1023588937 |
| 9 | 14402985777 |
| 10 | 202665398173 |
| 11 | 2851718540021 |
| 12 | 40126725007181 |
| 13 | 564625868522949 |
| 14 | 7944888884612393 |
| 15 | 111793070252410993 |
| 16 | 1573047872420021137 |
| 17 | 22134463284128711769 |
| 18 | 311455533850231631029 |
| 19 | 4382511937187348260781 |