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 | 9 |
| 2 | 81 |
| 3 | 271 |
| 4 | 1309 |
| 5 | 5371 |
| 6 | 23637 |
| 7 | 101069 |
| 8 | 438103 |
| 9 | 1887667 |
| 10 | 8151773 |
| 11 | 35161937 |
| 12 | 151744767 |
| 13 | 654767065 |
| 14 | 2825582407 |
| 15 | 12192964863 |
| 16 | 52615498559 |
| 17 | 227045509685 |
| 18 | 979746980809 |
| 19 | 4227807834119 |
| 20 | 18243882203687 |
| 21 | 78726167982599 |