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 | 2 |
| 1 | 8 |
| 2 | 34 |
| 3 | 152 |
| 4 | 706 |
| 5 | 3368 |
| 6 | 16354 |
| 7 | 80312 |
| 8 | 397186 |
| 9 | 1972808 |
| 10 | 9824674 |
| 11 | 49005272 |
| 12 | 244672066 |
| 13 | 1222297448 |
| 14 | 6108298594 |
| 15 | 30531927032 |
| 16 | 152630937346 |
| 17 | 763068593288 |
| 18 | 3815084686114 |
| 19 | 19074648589592 |
| 20 | 95370918425026 |
| 21 | 476847618556328 |