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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 15 |
| 6 | 32 |
| 7 | 88 |
| 8 | 209 |
| 9 | 539 |
| 10 | 1403 |
| 11 | 3698 |
| 12 | 9962 |
| 13 | 26447 |
| 14 | 71579 |
| 15 | 196590 |
| 16 | 541473 |
| 17 | 1501720 |
| 18 | 4186566 |
| 19 | 11737617 |
| 20 | 33005599 |
| 21 | 93296302 |