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 | 5 |
| 3 | 25 |
| 4 | 161 |
| 5 | 1081 |
| 6 | 8745 |
| 7 | 75305 |
| 8 | 741961 |
| 9 | 7904201 |
| 10 | 93174025 |
| 11 | 1185282185 |
| 12 | 16364262281 |
| 13 | 242055376521 |
| 14 | 3834244039305 |
| 15 | 64590031280265 |
| 16 | 1154392672267401 |
| 17 | 21796700933039241 |
| 18 | 433694961594395785 |
| 19 | 9066521908425387145 |
| 20 | 198692729793556061321 |