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 | 6 |
| 2 | 30 |
| 3 | 174 |
| 4 | 1038 |
| 5 | 6222 |
| 6 | 37326 |
| 7 | 223950 |
| 8 | 1343694 |
| 9 | 8062158 |
| 10 | 48372942 |
| 11 | 290237646 |
| 12 | 1741425870 |
| 13 | 10448555214 |
| 14 | 62691331278 |
| 15 | 376147987662 |
| 16 | 2256887925966 |
| 17 | 13541327555790 |
| 18 | 81247965334734 |
| 19 | 487487792008398 |
| 20 | 2924926752050382 |