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 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 29 |
| 4 | 132 |
| 5 | 589 |
| 6 | 2610 |
| 7 | 11537 |
| 8 | 50952 |
| 9 | 224953 |
| 10 | 993054 |
| 11 | 4383653 |
| 12 | 19350540 |
| 13 | 85417669 |
| 14 | 377052234 |
| 15 | 1664389721 |
| 16 | 7346972688 |
| 17 | 32431108081 |
| 18 | 143157839670 |
| 19 | 631929281453 |
| 20 | 2789470811028 |
| 21 | 12313319895997 |
| 22 | 54353623698786 |