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 | 6 |
| 1 | 31 |
| 2 | 181 |
| 3 | 1081 |
| 4 | 6481 |
| 5 | 38881 |
| 6 | 233281 |
| 7 | 1399681 |
| 8 | 8398081 |
| 9 | 50388481 |
| 10 | 302330881 |
| 11 | 1813985281 |
| 12 | 10883911681 |
| 13 | 65303470081 |
| 14 | 391820820481 |
| 15 | 2350924922881 |
| 16 | 14105549537281 |
| 17 | 84633297223681 |
| 18 | 507799783342081 |
| 19 | 3046798700052481 |
| 20 | 18280792200314881 |