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 | 3 |
| 2 | 15 |
| 3 | 117 |
| 4 | 627 |
| 5 | 8571 |
| 6 | 35649 |
| 7 | 699171 |
| 8 | 7898361 |
| 9 | 40404717 |
| 10 | 41219817 |
| 11 | 1300637127 |
| 12 | 22464584559 |
| 13 | 843217244283 |
| 14 | 854342788713 |
| 15 | 37181761691859 |
| 16 | 864748487122557 |
| 17 | 6116114629522299 |
| 18 | 6175362432667599 |
| 19 | 6231378537459519 |
| 20 | 182250420468103851 |