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 | 1 |
| 1 | 6 |
| 2 | 30 |
| 3 | 162 |
| 4 | 886 |
| 5 | 4932 |
| 6 | 27714 |
| 7 | 157018 |
| 8 | 894942 |
| 9 | 5126268 |
| 10 | 29481732 |
| 11 | 170128850 |
| 12 | 984577446 |
| 13 | 5712117772 |
| 14 | 33210790018 |
| 15 | 193456179430 |
| 16 | 1128789904110 |
| 17 | 6596174575548 |
| 18 | 38596967873100 |
| 19 | 226120320617484 |
| 20 | 1326180436400932 |